Get querystring parameter by name using javascript

gistfile1.js

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