/**
 * Retrieve a named parameter from the query string.
 * @param name of the parameter to retrieve. Returns a blank string if not found.
 */
function getQueryStringParameter(sMarker){
	sMarker = sMarker + "=";
	var sOut = document.location.href + "&?";
	var iPos = sOut.indexOf("?") + 1;
	sOut = sOut.substring(iPos);
	if(sOut != ""){
		iPos = sOut.indexOf(sMarker);
		if(iPos != -1){
			sOut = sOut.substring(iPos + sMarker.length, sOut.indexOf("&", iPos));
		} else {
			sOut = "";
		}
	}
	return sOut;
}