function isEmpty(s)
{   return ((s == null) || (s.length == 0))
}


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


function isInteger (s)
{   var i;
    if (isEmpty(s))
       if (isInteger.arguments.length == 1) return true;
       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;
        //}
    }
    return true;
}


function isNumber (s)
{   var i;
    var dotAppeared;
    dotAppeared = false;
    if (isEmpty(s))
       if (isNumber.arguments.length == 1) return true;
       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;
}


function isDate(myFecha) {
 var sNuevoFecha;
 var sItem = myFecha.value.split('/');
 if (sItem.length == 3) {
  var nDia, nMes;
  nDia = parseInt(sItem[0], 10);
  nMes = parseInt(sItem[1], 10);
  if (! (isNaN(nDia) || isNaN(nMes))) {
   if ((nDia == 31 && (nMes == 1 || nMes == 3 || nMes == 5 || nMes == 7 || nMes == 8 || nMes == 9 || nMes == 12)) || nDia < 31) {
    if (nDia >= 1 && nDia <= 31 && nMes >= 1 && nMes <= 12) {
     sNuevoFecha = nDia;
     if (nDia < 10) sNuevoFecha = '0' + sNuevoFecha;
     if (nMes < 10) sNuevoFecha = sNuevoFecha + '/' + '0' + nMes;
    else
     sNuevoFecha = sNuevoFecha + '/' + nMes;
     //myFecha.value = sNuevoFecha;
     return true;
    }
   }
  }
 }
 return false;
}

function isEmail(myEmail)
{
 var boleano;
 for(i=0 ; i<myEmail.length; i++)
 {
  boleano = 1;
  boleano = (myEmail.charAt(i) == '@') & boleano;
  if (boleano) break;
 }

 if (boleano)
 {
  for(i=0 ; i<myEmail.length; i++)
  {

   if (myEmail.charAt(i) == '.')
   {
    boleano = 1
    break;
   }
   boleano = 0
  }
 }
return(boleano)
}