JavaScript Function to get parts of the URL string

function getParameterByName(name, url) {
if (!url) url = window.location.href;
name = name.replace(/[\[\]]/g, "\\$&");
var regex = new RegExp("[?&]" + name + "(=([^&#]*)|&|#|$)"),
results = regex.exec(url);
if (!results) return '';
if (!results[2]) return '';
return decodeURIComponent(results[2].replace(/\+/g, " "));
}