Get query parameter by name from given URL

queryParameterByName.js

function queryParameterByName(name, querystring) {
    // See: http://stackoverflow.com/questions/901115/how-can-i-get-query-string-values-in-javascript

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

(function(){
    var urlString = "http://www.foo.com/my?name=foo&age=123";
    console.log("name: " + queryParameterByName("name", urlString));
    console.log("age : " + queryParameterByName("age", urlString));
    console.log("nada: " + queryParameterByName("nada", urlString));
})();