Query Parameter Parsing Using RegEx - http://www.netlobo.com/url_query_string_javascript.html

queryParams-regex.js

// Much faster than string splitting when you need to get a parameter
// http://jsperf.com/query-parameter-parsing

function gup(name) {
    name = name.replace(/[\[]/, "\\\[").replace(/[\]]/, "\\\]");
    var regexS = "[\\?&]" + name + "=([^&#]*)";
    var regex = new RegExp(regexS);
    var results = regex.exec(window.location.href);
    if (results == null) {
        return "";
    }
    else {
        return results[1];
    }
}