Get URL parameter

function gup( varname ) {
	varname = varname.replace(/[\[]/,"\\\[").replace(/[\]]/,"\\\]");
	var regexS = "[\\?&]"+varname+"=([^&#]*)";
	var regex = new RegExp( regexS );
	var results = regex.exec( window.location.href );
	if( results == null ) return ""; else return results[1];
}