Retrieve GET URL params

getUrlParameter.js

/**
 * Read url parameters
 *
 * @link http://stackoverflow.com/a/901144/5734037
 */
var getUrlParameter = function (name, url) {
    if (!url) url = window.location.href;
    name = name.replace(/[\[\]]/g, "\\$&");
    var regex = new RegExp("[?&]" + name + "(=([^&#]*)|&|#|$)"),
        results = regex.exec(url);
    if (!results) return null;
    if (!results[2]) return '';
    return decodeURIComponent(results[2].replace(/\+/g, " "));
};