Get query string values in JavaScript?

get-query-string-value-javascript.js

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

// Usage :: 
var queryVar = getParameterByName('key');