javascript url callback

var scripts = document.getElementsByTagName("script");

for (var i = 0; i < scripts.length; i++) {

    var url = scripts[i].src;

    // extract filename and callback parameter from the URL

    var matches = url.match(/\/([^\/]+)\?.*v=(.*?)(&|$)/);

    if (matches && matches[1] == "test.js") {

         call the callback function

        window[matches[2]]();

    }

}