// get query string paramter and return the value
function RequestQueryString(sParamName,isParentRequest)
{
	sParamName = sParamName.toLowerCase();
	var sHref="";
	var arrHref;
	var nParamStartPos=0, nParamEndPos=0;
	var sParamValue='';
	 
	sHref = typeof isParentRequest != 'undefined' ? sHref = parent.document.location.href  : sHref = document.location.href;	
		 
	arrHref = sHref.split("?");
	// return empty string if the query string not exsits
	if (arrHref.length <= 1) 
		return(sParamValue);
	sParamName += '=';
	nParamStartPos = arrHref[1].toLowerCase().indexOf(sParamName);
	// return empty string if the requested parameter is not exsits
	if(nParamStartPos == -1)	
		return(sParamValue);
	nParamStartPos += sParamName.toString().length;
	nParamEndPos = arrHref[1].indexOf("&", nParamStartPos);
	if(nParamStartPos == nParamEndPos)
		return '';
		
	if(nParamEndPos > -1 && nParamEndPos > nParamStartPos)
		sParamValue=arrHref[1].slice(nParamStartPos,nParamEndPos);
	else
		sParamValue=arrHref[1].slice(nParamStartPos);

	return(sParamValue);
}