Get url GET parameter value by name, depending on given url

getParameterByName.js

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

    }

/** Example :  We want to know if a param get "page" exist on our current url **/
 var results = getParameterByName('page', window.location);