//--------------------------
// Validate String function
//--------------------------
function checkString(theField,fieldName,maxLength,emptyOK) {
	
	if(isEmpty(theField.value) && emptyOK)
	   return true;
	else{
	
	     if (isWhiteSpace(theField.value) || ((theField.value).length > maxLength)){
	         if(emptyOK)
	           alert(fieldName + " cannot be greater than "+ maxLength +" charaters");
	         else
	           alert(fieldName + " cannot be blank or greater than "+ maxLength +" charaters");
	         theField.focus();
	         return false;
             }else
              return true;
	}
	
	
}


//check for correct date

function checkDate(theField,fieldName,emptyOK){
    
    if(isEmpty(theField.value) && emptyOK)return true;
    else{
	 if(isProperDate(theField.value))return true;
	 else{
	      alert(fieldName + " is inValid.");
	      theField.focus();
	      return false;
	 }
	   
    } 
}

//check for correct number

function checkNumber(theField,fieldName,emptyOK){
    
    if(isEmpty(theField.value) && emptyOK)return true;
    else{
	 if(isNumber(theField.value))return true;
	 else{
	      alert("Enter Correct " + fieldName);
	      theField.focus();
	      return false;
	 }
	   
    } 
}

//check for correct email id

function checkEmail(theField,maxLength,emptyOK){
    
    if(isEmpty(theField.value) && emptyOK)return true;
    else{
	 if(isEmail(theField.value) && ((theField.value).length < maxLength) )return true;
	 else{
	      alert("Enter correct Email Id");
	      theField.focus();
	      return false;
	 }
	   
    } 
}


//check if Selected or not

function checkSelect(theField,fieldName){
    
   if(theField.selectedIndex == 0){
      alert("Select the " + fieldName);
      theField.focus();
      return false;
   }
   return true;
	   
}

//check for valid email id

function isEmail (s)
{   
 
    // is s whitespace?
    if (isWhiteSpace(s)) return false;
    
    // there must be >= 1 character before @, so we
    // start looking at character position 1 
    // (i.e. second character)
    var i = 1;
    var sLength = s.length;

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

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

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

    // there must be at least one character after the .
    if ((i >= sLength - 1) || (s.charAt(i) != ".")) return false;
    else return true;
}


// Check whether string s is empty.

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


//--------------------------
// Validate number function
//--------------------------
function isNumber(argNum) {
	var tmpstr = "0123456789. ";
	var count=0
	for(var i=0;i < argNum.length;i++)
	  for(var j=0;j < tmpstr.length;j++)
	     if(argNum.charAt(i) == tmpstr.charAt(j))count++;
	     
	if(argNum.length == count)
	  return true;
	else
	  return false;
}

//------------------------------------------------------------------------------------
// function: isProperDate
//           Function to tell whether the given date is valid or not
//           This function expects date in the format of mm/dd/yyyy or mm/dd/yy
//           or mm-dd-yyyy or mm-dd-yy
//------------------------------------------------------------------------------------
function isProperDate(argDate) {
	var tmpDay = getDay(argDate)
	var tmpMon = getMonth(argDate)
	var tmpYear = getYear(argDate)

	return isProperDay(tmpDay, tmpMon, tmpYear) && isProperMonth(tmpMon) && isProperYear(tmpYear)
}

//------------------------------------------------------------------------------------
// function: isWhiteSpace
//           Function to check whether the given argument consists of charactes other
//           than a space and \t
//------------------------------------------------------------------------------------
function isWhiteSpace(argWhiteSpace) {
	argWs = argWhiteSpace.toString()
	
	for (var intI=0; intI < argWs.length; intI++)
		if (argWs.charAt(intI) != ' ' && argWs.charAt(intI) != '\t')
			return false
	
	return true
}

//------------------------------------------------------------------------------------
// function: isLeapYear
//           Function to tell, whether the given year is leap year or not
//------------------------------------------------------------------------------------
function isLeapYear(argYear) {
	return ((argYear % 4 == 0) && (argYear % 100 != 0)) || (argYear % 400 == 0) 
}

//------------------------------------------------------------------------------------
// function: daysInMonth
//           Function to return the maximum number of days in a given month of a
//           given year
//------------------------------------------------------------------------------------
function daysInMonth(argMonth, argYear) {
	switch (Number(argMonth)) {
		case 1:		// Jan
		case 3:		// Mar
		case 5:		// May
		case 7:		// Jul
		case 8:		// Aug
		case 10:		// Oct
		case 12:		// Dec
			return 31;
			break;
		
		case 4:		// Apr
		case 6:		// Jun
		case 9:		// Sep
		case 11:		// Nov
			return 30;
			break;
		
		case 2:		// Feb
			if (isLeapYear(argYear))
				return 29
			else
				return 28
			break;
		
		default:
			return 0;
	}
}

//------------------------------------------------------------------------------------
// function: getDateSeparator
//           Function to return the date separator
//           This function expects date in the format of mm/dd/yyyy or mm/dd/yy
//           or mm-dd-yyyy or mm-dd-yy
//------------------------------------------------------------------------------------
function getDateSeparator(argDate) {
	// Are there invalid separators?
	if ((argDate.indexOf('-') > 0) && (argDate.indexOf('/') > 0))
		return ' '

	if (argDate.indexOf('-') > 0)
		return '-'
	else
		if (argDate.indexOf('/') > 0)
			return '/'
		else
			return ' '
}

//------------------------------------------------------------------------------------
// function: getYear
//           Function to return the year part of the given date.
//           This function expects date in the format of mm/dd/yyyy or mm/dd/yy
//           or mm-dd-yyyy or mm-dd-yy
//------------------------------------------------------------------------------------
function getYear(argDate) {
	var dateSep = getDateSeparator(argDate)
	
	if (dateSep == ' ')
		return 0

	if(argDate.split(dateSep).length == 3)
		return argDate.split(dateSep)[2]
	else
		return 0
}

//------------------------------------------------------------------------------------
// function: getMonth
//           Function to return the month part of the given date.
//           This function expects date in the format of mm/dd/yyyy or mm/dd/yy
//           or mm-dd-yyyy or mm-dd-yy
//------------------------------------------------------------------------------------
function getMonth(argDate) {
	var dateSep = getDateSeparator(argDate)
	
	if (dateSep == ' ')
		return 0

	if(argDate.split(dateSep).length == 3)
		return argDate.split(dateSep)[0]
	else
		return 0
}

//------------------------------------------------------------------------------------
// function: getDay
//           Function to return the day part of the given date.
//           This function expects date in the format of mm/dd/yyyy or mm/dd/yy
//           or mm-dd-yyyy or mm-dd-yy
//------------------------------------------------------------------------------------
function getDay(argDate) {
	var dateSep = getDateSeparator(argDate)
	
	if (dateSep == ' ')
		return 0

	if(argDate.split(dateSep).length == 3)
		return argDate.split(dateSep)[1]
	else
		return 0
}

//------------------------------------------------------------------------------------
// function: isProperDay
//           Function to tell whether the given day of the given month is valid
//------------------------------------------------------------------------------------
function isProperDay(argDay, argMonth, argYear) {
	if ((isWhiteSpace(argDay)) || (argDay == 0))
		return false

	if ((argDay > 0) && (argDay < daysInMonth(argMonth, argYear) + 1))
		return true
	else 
		return false
}

//------------------------------------------------------------------------------------
// function: isProperMonth
//           Function to tell whether the given month is a valid one
//------------------------------------------------------------------------------------
function isProperMonth(argMonth) {
	if ((isWhiteSpace(argMonth)) || (argMonth == 0))
		return false
	
	if ((argMonth > 0) && (argMonth < 13))
		return true
	else
		return false
}

//------------------------------------------------------------------------------------
// function: isProperYear
//           Function to tell whether the given Year is a valid one
//------------------------------------------------------------------------------------
function isProperYear(argYear) {
	if ((isWhiteSpace(argYear)) || (argYear.toString().length > 4) || (argYear.toString().length == 3))
		return false
	
	switch (argYear.toString().length) {
		case 1:
			if (argYear >=0 && argYear < 10)
				return true
			else
				return false
			
		case 2:
			if (argYear >=0 && argYear < 100)
				return true
			else
				return false
			
		case 4:
			if (((argYear >=1900) || (argYear >=2000)) && ((argYear < 3000) || (argYear < 2000)))
				return true
			else
				return false
		
		default:
			return false
	}
}