function popup() {
    window.open(this.href, 'gc_popup', 'height=690,width=670,scrollbars=yes').focus();
}

$(document).ready( function () {
    $("#menu-popup").click(function (e) {
        window.open($("#menu-popup").attr('href'), 'gc_chart', 'height=600,width=800,scrollbars=yes').focus();
        e.preventDefault();
    });
});