//save the clickID parameter in a cookie called clickID
var urlParams = new URLSearchParams(window.location.search);
var clickID = urlParams.get('clickID');
if (clickID) {

    var d = new Date();
    d.setTime(d.getTime() + (30 * 24 * 60 * 60 * 1000));
    var expires = "expires=" + d.toUTCString();
    document.cookie = "clickID=" + clickID + ";" + expires + ";path=/";

}