function centerPOP(w, h, url, name, opt) {
    var there = null;
    if (window.screen) {
        var hor = screen.availWidth;
        var ver = screen.availHeight;
        there = window.open(url, name, 'width=' + w + ',height=' + h + ',left=' + ((hor - w - 10) * .5) + ',top=' + ((ver - h - 30) * .5) + ',scrollbars=' + opt + ',');
    }
}