function user_login() {
    var obj = showModalDialog("pop_login.aspx?Rnd=" + Math.random(), 'login', 'dialogWidth:390px;dialogHeight:300px;help:0;status:0;resizeable:1');
    //alert(obj);
    if (typeof (obj) == "undefined") return false;

    window.location.href = document.URL;
}