<!-- 

function _isDate()
{

	var isDate = new Date(this);
	 
	if ( (isNaN(isDate)) || (isDate == "Invalid Date") )
	{
		return false;
	}
	else
	{
		return true;
	}
	
}

function _trim()
{
	return this.replace(/^\s+/,'').replace(/\s+$/,'');
}

function _isNumeric() 
{

	var dontCalculateFlag = 0;
	var decimalFlag = 0;
	var ch = "";

	for (var i = 0; i < this.length; i++)
	{

		ch = this.substring(i, i + 1);
			             
		if ((ch < "0" || "9" < ch) && ch != "." && ch != "-")
		{
		   dontCalculateFlag = 1;
		}
	             
		if (ch == "." && decimalFlag== 1)
		{
			dontCalculateFlag = 1;
		}

		if (ch == ".")
		{
			decimalFlag = 1;
		}

	}
	   
	if (dontCalculateFlag == 1)
	{
	 	return false;
	}
	else
	{
	 	return true;
	}

}

function _replace(strSearchText, strReplaceText) {

    var i = 0;
    var strNewString = '';
    
	var strOriginalString = this;
	
    i = strOriginalString.indexOf(strSearchText);
    
    //check for trivial case
    //
    if ( (!i) || (i == -1) )
    {
		strNewString = strOriginalString;
	}
	else
    {
		strNewString += strOriginalString.substring(0,i) + strReplaceText;

		if (i+strSearchText.length < strOriginalString.length) 
		{
			//recurse where necessary
			//
		    strNewString += replace(strOriginalString.substring(i+strSearchText.length,strOriginalString.length), strSearchText, strReplaceText);
		}
    }
    
    //return the value
    //
    return strNewString;
    
}

String.prototype.trim = _trim;
String.prototype.isDate = _isDate;
String.prototype.isNumeric = _isNumeric;
String.prototype.replace = _replace;

//-->