//For checking Null values
	function trimWhiteSpace(aStr)
	{
	     var ch = aStr.substring(0, 1);
         while (ch == " ")
         { // Check for spaces at the beginning of the string
           aStr = aStr.substring(1, aStr.length);
           ch = aStr.substring(0, 1);
         }
         
    
        
        ch = aStr.substring(aStr.length-1, aStr.length);
        while (ch == " ") 
          { // Check for spaces at the end of the string
           aStr = aStr.substring(0, aStr.length-1);
           ch = aStr.substring(aStr.length-1, aStr.length);
         }       
         
         return aStr ; 
	
	}

	function isNull(aStr)
	{
		var index;		
		for (index=0; index < aStr.length; index++)
			if (aStr.charAt(index) != ' ')
				return false;
		return true;
	}
	
	//For checking invalid E-Mail address

	function isEmail(aStr){
	
	     var ch = aStr.substring(0, 1);
         while (ch == " ")
         { // Check for spaces at the beginning of the string
           aStr = aStr.substring(1, aStr.length);
           ch = aStr.substring(0, 1);
         }
         
    
        
        ch = aStr.substring(aStr.length-1, aStr.length);
        while (ch == " ") 
          { // Check for spaces at the end of the string
           aStr = aStr.substring(0, aStr.length-1);
           ch = aStr.substring(aStr.length-1, aStr.length);
         }

        ch=aStr
        
         
		var reEmail=/^[0-9a-zA-Z_\.-]+\@[0-9a-zA-Z_\.-]+\.[0-9a-zA-Z_\.-]+$/;
		if(!reEmail.test(aStr))
		{
			return false;
		}
		return true;
	}

   function isAlphaNumeric(aStr)
   {
        var reAlphanumeric = /^[a-zA-Z0-9]+$/;
        if(!reAlphanumeric.test(aStr))
		{
			return false;
		}
		return true;
   } 

//check validity of date
function checkDate(dt)
{
	var reg = new RegExp("[0-9]{1,2}/[0-9]{1,2}/[0-9]{4}$");
	if(reg.test(dt))
	{
		var datepart = dt.split("/");
		for(i=0;i<datepart.length;i++)
			datepart[i] = parseFloat(datepart[i]);
		if(datepart[1] > 31 || datepart[0] > 12)
			return false;
		else if((datepart[0] == 4 || datepart[0] == 6 || datepart[0] == 9 || datepart[0] == 11) && datepart[1] == 31)
			return false;	
		else if(datepart[0] == 2)
		{
			if(datepart[1] > 29)
				return false;
			if(!LeapYear(datepart[2]) && datepart[1] == 29)
				return false;
		}
		return true;						
	}
	return false;			
}


function LeapYear(intYear) {
	if (intYear % 100 == 0) {
		if (intYear % 400 == 0) { return true; }
	}
	else { 
		if ((intYear % 4) == 0) { return true; }
	}
	return false;
}