// ---------------------------------------------------------------------- //
//                                VARIABLES                               //
// ---------------------------------------------------------------------- //

// Esta variable indica si está bien dejar las casillas
// en blanco como regla general
var defaultEmptyOK = false

// Esta variable indica si se debe verificar la presencia de comillas
// u otros símbolos extraños en un campo, por omisión no, porque
// siempre crea problemas con las bases de datos o programas CGI
var checkNiceness = true;

// listas de caracteres
var digits = "0123456789";
var lowercaseLetters = "abcdefghijklmnopqrstuvwxyzáéíóúñü"
var uppercaseLetters = "ABCDEFGHIJKLMNOPQRSTUVWXYZÁÉÍÓÚÑ"
var whitespace = " \t\n\r";

// caracteres admitidos en nos de telefono
var phoneChars = "()-+ ";

// ---------------------------------------------------------------------- //
//                     TEXTOS PARA LOS MENSAJES                           //
// ---------------------------------------------------------------------- //

// m abrevia "missing" (faltante)
var mMessage = "Error: no puede dejar este espacio vacio"

// p abrevia "prompt"
var pPrompt = "Error: ";
var pAlphanumeric = "ingrese un texto que contenga solo letras y/o numeros";
var pAlphabetic   = "ingrese un texto que contenga solo letras";
var pInteger = "ingrese un número entero";
var pNumber = "ingrese un número";
var pNumberV = "ingrese un número mayor a 0";
var pPhoneNumber = "ingrese un número de teléfono";
var pEmail = "ingrese una dirección de correo electrónico válida";
var pName = "ingrese un texto que contenga solo letras, numeros o espacios";
var pNice = "no puede utilizar comillas aqui";
var pDate = "ingrese una fecha válida en formato dd/mm/yyyy"
var pYear = "ingrese un año válido (4 dígitos)"
var pMonth = "ingrese un mes válido (1 - 12)"
var pDocumento = "número de documento no válido"
var pSelect = "seleccione un valor de la lista"

// ---------------------------------------------------------------------- //
//                FUNCIONES PARA MANEJO DE ARREGLOS                       //
// ---------------------------------------------------------------------- //

// JavaScript 1.0 (Netscape 2.0) no tenia un constructor para arreglos,
// asi que ellos tenian que ser hechos a mano. Desde JavaScript 1.1 
// (Netscape 3.0) en adelante, las funciones de manejo de arreglos no
// son necesarias.

function makeArray(n) {
//*** BUG: If I put this line in, I get two error messages:
//(1) Window.length can't be set by assignment
//(2) daysInMonth has no property indexed by 4
//If I leave it out, the code works fine.
//   this.length = n;
   for (var i = 1; i <= n; i++) {
      this[i] = 0
   } 
   return this
}

// ---------------------------------------------------------------------- //
//                  CANTIDAD DE DIAS DE LOS MESES                         //
// ---------------------------------------------------------------------- //
var daysInMonth = makeArray(12);
daysInMonth[1] = 31;
daysInMonth[2] = 29;   // must programmatically check this
daysInMonth[3] = 31;
daysInMonth[4] = 30;
daysInMonth[5] = 31;
daysInMonth[6] = 30;
daysInMonth[7] = 31;
daysInMonth[8] = 31;
daysInMonth[9] = 30;
daysInMonth[10] = 31;
daysInMonth[11] = 30;
daysInMonth[12] = 31;

// ---------------------------------------------------------------------- //
//                  CODIGO PARA FUNCIONES BASICAS                         //
// ---------------------------------------------------------------------- //

function UCase(s){
	return s.toUpperCase();
}

// s es vacio
function isEmpty(s)
{   
	s = stripWhitespace(s);
	return ((s == null) || (s.length == 0));
}

// s es vacio o solo caracteres de espacio
function isWhitespace (s)
{   var i;
    if (isEmpty(s)) return true;
    for (i = 0; i < s.length; i++)
    {   
        var c = s.charAt(i);
        // si el caracter en que estoy no aparece en whitespace,
        // entonces retornar falso
        if (whitespace.indexOf(c) == -1) return false;
    }
    return true;
}

// Quita todos los caracteres que que estan en "bag" del string "s" s.
function stripCharsInBag (s, bag)
{   var i;
    var returnString = "";

    // Buscar por el string, si el caracter no esta en "bag", 
    // agregarlo a returnString
    
    for (i = 0; i < s.length; i++)
    {   var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }

    return returnString;
}

// Lo contrario, quitar todos los caracteres que no estan en "bag" de "s"
function stripCharsNotInBag (s, bag)
{   var i;
    var returnString = "";
    for (i = 0; i < s.length; i++)
    {   
        var c = s.charAt(i);
        if (bag.indexOf(c) != -1) returnString += c;
    }

    return returnString;
}

// Quitar todos los espacios en blanco de un string
function stripWhitespace (s)
{   return stripCharsInBag (s, whitespace)
}

// La rutina siguiente es para cubrir un bug en Netscape
// 2.0.2 - seria mejor usar indexOf, pero si se hace
// asi stripInitialWhitespace() no funcionaria

function charInString (c, s)
{   for (i = 0; i < s.length; i++)
    {   if (s.charAt(i) == c) return true;
    }
    return false
}

// Quita todos los espacios que antecedan al string
function stripInitialWhitespace (s)
{   var i = 0;
    while ((i < s.length) && charInString (s.charAt(i), whitespace))
       i++;
    return s.substring (i, s.length);
}

// c es una letra del alfabeto espanol
function isLetter (c)
{
    return( ( uppercaseLetters.indexOf( c ) != -1 ) ||
            ( lowercaseLetters.indexOf( c ) != -1 ) )
}

// c es un digito
function isDigit (c)
{   return ((c >= "0") && (c <= "9"))
}

// c es letra o digito
function isLetterOrDigit (c)
{   return (isLetter(c) || isDigit(c))
}

function isSignedInteger (s)

{   if (isEmpty(s)) 
       if (isSignedInteger.arguments.length == 1) return defaultEmptyOK;
       else return (isSignedInteger.arguments[1] == true);

    else {
        var startPos = 0;
        var secondArg = defaultEmptyOK;

        if (isSignedInteger.arguments.length > 1)
            secondArg = isSignedInteger.arguments[1];

        // skip leading + or -
        if ( (s.charAt(0) == "-") || (s.charAt(0) == "+") )
           startPos = 1;    
        return (isInteger(s.substring(startPos, s.length), secondArg))
    }
}

function isNonnegativeInteger (s)
{   var secondArg = defaultEmptyOK;

    if (isNonnegativeInteger.arguments.length > 1)
        secondArg = isNonnegativeInteger.arguments[1];

    return (isSignedInteger(s, secondArg)
         && ( (isEmpty(s) && secondArg)  || (parseInt (s) >= 0) ) );
}

// ---------------------------------------------------------------------- //
//                          NUMEROS                                       //
// ---------------------------------------------------------------------- //

// s es un numero entero (con o sin signo)
function isInteger (s)
{   var i;
    if (isEmpty(s)) 
       if (isInteger.arguments.length == 1) return defaultEmptyOK;
       else return (isInteger.arguments[1] == true);
    
    for (i = 0; i < s.length; i++)
    {   
        var c = s.charAt(i);
        if( i != 0 ) {
            if (!isDigit(c)) return false;
        } else { 
            if (!isDigit(c) && (c != "-") || (c == "+")) return false;
        }
    }
    return true;
}

// s es un numero (entero o flotante, con o sin signo)
function isNumber (s)
{   var i;
    var dotAppeared;
    dotAppeared = false;
    if (isEmpty(s)) 
       if (isNumber.arguments.length == 1) return defaultEmptyOK;
       else return (isNumber.arguments[1] == true);
    
    for (i = 0; i < s.length; i++)
    {   
        var c = s.charAt(i);
        if( i != 0 ) {
            if ( c == "." ) {
                if( !dotAppeared )
                    dotAppeared = true;
                else
                    return false;
            } else     
                if (!isDigit(c)) return false;
        } else { 
            if ( c == "." ) {
                if( !dotAppeared )
                    dotAppeared = true;
                else
                    return false;
            } else     
                if (!isDigit(c) && (c != "-") || (c == "+")) return false;
        }
    }
    return true;
}

// s es un numero (entero o flotante, con o sin signo)
function isNumberV (s)
{   var i;
    var dotAppeared;
    dotAppeared = false;
    if (isEmpty(s)) 
       if (isNumberV.arguments.length == 1) return defaultEmptyOK;
       else return (isNumberV.arguments[1] == true);
    
    for (i = 0; i < s.length; i++)
    {   
        var c = s.charAt(i);
        if( i != 0 ) {
            if ( c == "." ) {
                if( !dotAppeared )
                    dotAppeared = true;
                else
                    return false;
            } else     
                if (!isDigit(c)) return false;
        } else { 
            if ( c == "." ) {
                if( !dotAppeared )
                    dotAppeared = true;
                else
                    return false;
            } else     
                if (!isDigit(c) && (c != "-") || (c == "+")) return false;
        }
    }
    
	return (s > 0);
}

function isIntegerInRange (s, a, b)
{   if (isEmpty(s)) 
       if (isIntegerInRange.arguments.length == 1) return defaultEmptyOK;
       else return (isIntegerInRange.arguments[1] == true);

    // Catch non-integer strings to avoid creating a NaN below,
    // which isn't available on JavaScript 1.0 for Windows.
    if (!isInteger(s, false)) return false;

    // Now, explicitly change the type to integer via parseInt
    // so that the comparison code below will work both on 
    // JavaScript 1.2 (which typechecks in equality comparisons)
    // and JavaScript 1.1 and before (which doesn't).
    var num = parseInt (s,10); // se agregó la base 10 JFZ
    return ((num >= a) && (num <= b));
}

// ---------------------------------------------------------------------- //
//                        COMBOS                                          //
// ---------------------------------------------------------------------- //
function isSelected (s)
{
	return (s.selectedIndex > 0)
}

// ---------------------------------------------------------------------- //
//                        STRINGS SIMPLES                                 //
// ---------------------------------------------------------------------- //

// s tiene solo letras
function isAlphabetic (s)
{   var i;

    if (isEmpty(s)) 
       if (isAlphabetic.arguments.length == 1) return defaultEmptyOK;
       else return (isAlphabetic.arguments[1] == true);
    for (i = 0; i < s.length; i++)
    {   
        // Check that current character is letter.
        var c = s.charAt(i);

        if (!isLetter(c))
        return false;
    }
    return true;
}


// s tiene solo letras y numeros
function isAlphanumeric (s)
{   var i;

    if (isEmpty(s)) 
       if (isAlphanumeric.arguments.length == 1) return defaultEmptyOK;
       else return (isAlphanumeric.arguments[1] == true);

    for (i = 0; i < s.length; i++)
    {   
        var c = s.charAt(i);
        if (! (isLetter(c) || isDigit(c) ) )
        return false;
    }

    return true;
}

// s tiene solo letras, numeros o "-"
function isNumExpediente (s)
{
	var i;
	
    if (isEmpty(s)) 
       if (isNumExpediente.arguments.length == 1) return defaultEmptyOK;
       else return (isNumExpediente.arguments[1] == true);

    for (i = 0; i < s.length; i++)
    {   
        var c = s.charAt(i);
        if (! ((isLetter(c) || isDigit(c)) || (c == "-")))
        return false;
    }
	
	if ((s.substring(0,1) == "-") || (s.substring(s.length - 1,s.length) == "-"))
		return false;
		
    return true;
}

// s tiene solo letras, numeros o espacios en blanco
function isName (s)
{
    if (isEmpty(s)) 
       if (isName.arguments.length == 1) return defaultEmptyOK;
       else return (isAlphanumeric.arguments[1] == true);
    
    return( isAlphanumeric( stripCharsInBag( s, whitespace ) ) );
}

// ---------------------------------------------------------------------- //
//                              FECHAS                                    //
// ---------------------------------------------------------------------- //
function daysInFebruary (year)
{   // February has 29 days in any year evenly divisible by four,
    // EXCEPT for centurial years which are not also divisible by 400.
    return (  ((year % 4 == 0) && ( (!(year % 100 == 0)) || (year % 400 == 0) ) ) ? 29 : 28 );
}

function isDay (s)
{   if (isEmpty(s)) 
       if (isDay.arguments.length == 1) return defaultEmptyOK;
       else return (isDay.arguments[1] == true);   
    return isIntegerInRange (s, 1, 31);
}

function isMonth (s)
{   if (isEmpty(s)) 
       if (isMonth.arguments.length == 1) return defaultEmptyOK;
       else return (isMonth.arguments[1] == true);      
    return isIntegerInRange (s, 1, 12);
}

function isYear (s)
{   if (isEmpty(s)) 
       if (isYear.arguments.length == 1) return defaultEmptyOK;
       else return (isYear.arguments[1] == true);
    if (!isNonnegativeInteger(s)) return false;
    //return ((s.length == 2) || (s.length == 4));
    return (s.length == 4);
}

// s es una Fecha en este formato dd/mm/yyy
function isDate (s)
{   
	var aDate = s.split("/")
	
	if (aDate.length != 3) return false;
	
	day		= aDate[0];
	month	= aDate[1];
	year	= aDate[2];
	
	// catch invalid years (not 2- or 4-digit) and invalid months and days.
    if (! (isYear(year, false) && isMonth(month, false) && isDay(day, false))) return false;

    // Explicitly change type to integer to make code work in both
    // JavaScript 1.1 and JavaScript 1.2.
    var intYear = parseInt(year);
    var intMonth = parseInt(month,10);
    var intDay = parseInt(day,10);
	
    // catch invalid days, except for February
    if (intDay > daysInMonth[intMonth]) return false; 

    if ((intMonth == 2) && (intDay > daysInFebruary(intYear))) return false;

    return true;
}

/*	
Original
function isDate (year, month, day)
{   // catch invalid years (not 2- or 4-digit) and invalid months and days.
    if (! (isYear(year, false) && isMonth(month, false) && isDay(day, false))) return false;

    // Explicitly change type to integer to make code work in both
    // JavaScript 1.1 and JavaScript 1.2.
    var intYear = parseInt(year);
    var intMonth = parseInt(month);
    var intDay = parseInt(day);

    // catch invalid days, except for February
    if (intDay > daysInMonth[intMonth]) return false; 

    if ((intMonth == 2) && (intDay > daysInFebruary(intYear))) return false;

    return true;
}
*/
// ---------------------------------------------------------------------- //
//                           FONO o EMAIL                                 //
// ---------------------------------------------------------------------- //

// s es numero de telefono valido
function isPhoneNumber (s)
{   var modString;
    if (isEmpty(s)) 
       if (isPhoneNumber.arguments.length == 1) return defaultEmptyOK;
       else return (isPhoneNumber.arguments[1] == true);
    modString = stripCharsInBag( s, phoneChars );
    return (isInteger(modString))
}

// s es una direccion de correo valida
function isEmail (s)
{
    if (isEmpty(s)) 
       if (isEmail.arguments.length == 1) return defaultEmptyOK;
       else return (isEmail.arguments[1] == true);
    if (isWhitespace(s)) return false;
    var i = 1;
    var sLength = s.length;
    while ((i < sLength) && (s.charAt(i) != "@"))
    { i++
    }

    if ((i >= sLength) || (s.charAt(i) != "@")) return false;
    else i += 2;

    while ((i < sLength) && (s.charAt(i) != "."))
    { i++
    }

    if ((i >= sLength - 1) || (s.charAt(i) != ".")) return false;
    else return true;
}

function isNice(s)
{
        var i = 1;
        var sLength = s.length;
        var b = 1;
        while(i<sLength) {
                if( (s.charAt(i) == "\"") || (s.charAt(i) == "'" ) ) b = 0;
                i++;
        }
        return b;
}

// ---------------------------------------------------------------------- //
//                  FUNCIONES PARA RECLAMARLE AL USUARIO                  //
// ---------------------------------------------------------------------- //

// pone el string s en la barra de estado
function statBar (s)
{   window.status = s
}

// notificar que el campo theField esta vacio
function warnEmpty (theField)
{   theField.focus()
    alert(mMessage)
    statBar(mMessage)
    return false
}

// notificar que el campo theField es invalido
function warnInvalid (theField, s)
{   theField.focus()
    theField.select()
    alert(s)
    statBar(pPrompt + s)
    return false
}

// notificar que el campo theField no ha sido seleccionado
function warnNoSelected(theField,s)
{
	theField.focus();
	alert(s)
    statBar(pPrompt + s)
    return false
}

// el corazon de todo: checkField
function checkField (theField, theFunction, emptyOK, s)
{   
    var msg;
    if (checkField.arguments.length < 3) emptyOK = defaultEmptyOK;
    if (checkField.arguments.length == 4) {
        msg = s;
    } else {
        if( theFunction == isAlphabetic ) msg = pAlphabetic;
        if( theFunction == isAlphanumeric ) msg = pAlphanumeric;
        if( theFunction == isInteger ) msg = pInteger;
        if( theFunction == isNumber ) msg = pNumber;
        if( theFunction == isNumberV ) msg = pNumberV;
        if( theFunction == isEmail ) msg = pEmail;
        if( theFunction == isPhoneNumber ) msg = pPhoneNumber;
        if( theFunction == isName ) msg = pName;
        if( theFunction == isSelected ) msg = pSelect;
        if( theFunction == isNumExpediente ) msg = pDocumento;
        if( theFunction == isYear ) msg = pYear;
        if( theFunction == isDate ) msg = pDate;
        if( theFunction == isMonth ) msg = pMonth;
    }
    
    if (theFunction == isSelected)
	{
		if (!(isSelected(theField)))
			return warnNoSelected(theField,msg)
		return true;
	}
		
    if ((emptyOK == true) && (isEmpty(theField.value))) return true;

    if ((emptyOK == false) && (isEmpty(theField.value))) 
        return warnEmpty(theField);
	
	if (checkNiceness && !isNice(theField.value))
		return warnInvalid(theField, pNice);

    if (theFunction(theField.value) == true) 
        return true;
    else
        return warnInvalid(theField,msg);

}