window.onload = function() {
    // Parse the URL
    function getParameterByName(name) {
        var name = name.replace(/[\[]/, "\\[").replace(/[\]]/, "\\]");
        var regex = new RegExp("[\\?&]" + name + "=([^&#]*)");
        var results = regex.exec(location.search);
        return results === null ? "" : decodeURIComponent(results[1].replace(/\+/g, " "));
    }
    // Give the URL parameters variable names
    var source = getParameterByName('utm_source');
    var medium = getParameterByName('utm_medium');
    var campaign = getParameterByName('utm_campaign');

    // Put the variable names into the hidden fields in the form.
    document.getElementById("property_utm_source").value = source;
    document.getElementById("property_utm_medium").value = medium;
    document.getElementById("property_utm_campaign").value = campaign;

    //U Can use it with Expertsender Forms
}