// TRIM FUNCTION => START
			function LTrim(String)
			{
				var i = 0;
				var j = String.length - 1;
			
				if (String == null)
					return (false);
			
				for (i = 0; i < String.length; i++)
				{
					if (String.substr(i, 1) != ' ' &&
						String.substr(i, 1) != '\t')
						break;
				}
			
				if (i <= j)
					return (String.substr(i, (j+1)-i));
				else
					return ('');
			}
			
			function RTrim(String)
			{
				var i = 0;
				var j = String.length - 1;
			
				if (String == null)
					return (false);
			
				for(j = String.length - 1; j >= 0; j--)
				{
					if (String.substr(j, 1) != ' ' &&
						String.substr(j, 1) != '\t')
					break;
				}
			
				if (i <= j)
					return (String.substr(i, (j+1)-i));
				else
					return ('');
			}
			
			function Trim(String)
			{
				if (String == null)
					return (false);
			
				return RTrim(LTrim(String));
			}
//TRIM FUNCTION => END 

function ClearErrorMsg(objControl,objSpan)
{
if(document.getElementById(objControl).type=='text')
{
    if (document.getElementById(objControl).value!="")
    {
    document.getElementById(objSpan).innerHTML="";
    }
}
else if (document.getElementById(objControl).type=='select-one')
{
         if (document.getElementById(objControl).value!=0)
    {
    document.getElementById(objSpan).innerHTML="";
    }
}
}

function checkforAmount(objText)
    {
       // alert(event.keyCode);
	    if(((event.keyCode<=57) && (event.keyCode>=48)) || (event.keyCode == 46)) 
	    {
	        var strnum = new String("" + objText.value);
	        if((strnum.indexOf(".")!= -1) && (event.keyCode == 46))
	        {
	            event.keyCode = 0
	        }
	        else
	        {	    
	            event.keyCode = event.keyCode;
	        }	        
	    }
	    else
	    {
	        event.keyCode = 0
	    }
	}
	
	function checkforNumber(objText)
    {
       //alert(event.keyCode);
	    if(((event.keyCode<=57) && (event.keyCode>=48))) 
	    {
	        var strnum = new String("" + objText.value);
	        if((strnum.indexOf(".")!= -1) && (event.keyCode == 46))
	        {
	            event.keyCode = 0
	        }
	        else
	        {	    
	            event.keyCode = event.keyCode;
	        }	        
	    }
	    else
	    {
	        event.keyCode = 0
	    }
	}

 function ClearErrorLogin(objControl,objSpan)
{
if(document.getElementById(objControl).type=='text')
{
    if (document.getElementById(objControl).value!="")
    {
    document.getElementById(objSpan).innerHTML="";
    }
}
else if (document.getElementById(objControl).type=='password')
{
         if (document.getElementById(objControl).value!="")
    {
    document.getElementById(objSpan).innerHTML="";
    }
}
else if (document.getElementById(objControl).type=='select-one')
{
         if (document.getElementById(objControl).value!="")
    {
    document.getElementById(objSpan).innerHTML="";
    }
}
}

function checkforDate(objText)
    {
       //alert(event.keyCode);
	    if((event.keyCode<=57) && (event.keyCode>=48) || (event.keyCode == 47) || (event.keyCode == 46)) 
	    {
	        var strnum = new String("" + objText.value);
	        if((strnum.indexOf(".")!= -1) && (event.keyCode == 100))
	        {
	            event.keyCode = 0
	        }
	        else
	        {	    
	            event.keyCode = event.keyCode;
	        }	        
	    }
	    else
	    {
	        event.keyCode = 0
	    }
	}
	
	
var dtCh= "/";
var minYear=1900;
var maxYear=2100;

function isInteger(s){
	var i;
    for (i = 0; i < s.length; i++){   
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    // All characters are numbers.
    return true;
}

function stripCharsInBag(s, bag){
	var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not in bag, append to returnString.
    for (i = 0; i < s.length; i++){   
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}

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 DaysArray(n) {
	for (var i = 1; i <= n; i++) {
		this[i] = 31
		if (i==4 || i==6 || i==9 || i==11) {this[i] = 30}
		if (i==2) {this[i] = 29}
   } 
   return this
}

function isDate(dtStr){
	var daysInMonth = DaysArray(12)
	var pos1=dtStr.indexOf(dtCh)
	var pos2=dtStr.indexOf(dtCh,pos1+1)
	var strDay=dtStr.substring(0,pos1)
	var strMonth=dtStr.substring(pos1+1,pos2)
	var strYear=dtStr.substring(pos2+1)
	strYr=strYear
	if (strDay.charAt(0)=="0" && strDay.length>1) strDay=strDay.substring(1)
	if (strMonth.charAt(0)=="0" && strMonth.length>1) strMonth=strMonth.substring(1)
	for (var i = 1; i <= 3; i++) {
		if (strYr.charAt(0)=="0" && strYr.length>1) strYr=strYr.substring(1)
	}
	month=parseInt(strMonth)
	day=parseInt(strDay)
	year=parseInt(strYr)
	if (pos1==-1 || pos2==-1){
		//alert("The date format should be : dd/mm/yyyy")
		return false
	}
	if (strMonth.length<1 || month<1 || month>12){
		//alert("Please enter a valid month")
		return false
	}
	if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
		//alert("Please enter a valid day")
		return false
	}
	if (strYear.length != 4 || year==0 || year<minYear || year>maxYear){
		//alert("Please enter a valid 4 digit year between "+minYear+" and "+maxYear)
		return false
	}
	if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
		//alert("Please enter a valid date")
		return false
	}
return true
}

 <!-- EMAIL CHEAKER  => START //-->  
   var good;
	function checkEmailAddress(field,spanMsg) 
{
    if(document.getElementById(field).value!="")
	{
		// Note: The next expression must be all on one line...
		//       allow no spaces, linefeeds, or carriage returns!
		var goodEmail = document.getElementById(field).value.match(/\b(^(\S+@).+((\.com)|(\.in)|(\.net)|(\.edu)|(\.mil)|(\.gov)|(\.org)|(\..{2,2}))$)\b/gi);
		if (!goodEmail)
		{
		   alert('Please enter a valid E-Mail address.');
		   document.getElementById(field).focus();
		   document.getElementById(field).select();
		   good = false;
		 }
		 else
	    {
	    document.getElementById(spanMsg).innerHTML="";
	    }
	}
}
<!-- EMAIL CHEAKER  => END //-->

function KeySortDropDownList_onkeypress (dropdownlist,caseSensitive) {
  // check the keypressBuffer attribute is defined on the dropdownlist
  var undefined; 
  if (dropdownlist.keypressBuffer == undefined) { 
    dropdownlist.keypressBuffer = ''; 
  } 
  // get the key that was pressed 
  var key = String.fromCharCode(window.event.keyCode); 
  dropdownlist.keypressBuffer += key;
  if (!caseSensitive) {
    // convert buffer to lowercase
    dropdownlist.keypressBuffer = dropdownlist.keypressBuffer.toLowerCase();
  }
  // find if it is the start of any of the options 
  var optionsLength = dropdownlist.options.length; 
  for (var n=0; n < optionsLength; n++) { 
    var optionText = dropdownlist.options[n].text; 
    if (!caseSensitive) {
      optionText = optionText.toLowerCase();
    }
    if (optionText.indexOf(dropdownlist.keypressBuffer,0) == 0) { 
      dropdownlist.selectedIndex = n; 
      return false; // cancel the default behavior since 
                    // we have selected our own value 
    } 
  } 
  // reset initial key to be inline with default behavior 
  dropdownlist.keypressBuffer = key; 
  return true; // give default behavior 
}