function openGallery(prmGallery){
    w = 720;
    h = 570;
    
    h = h - 20; var x=0, y=0, parameter="";
    if (w < screen.availWidth || h < screen.availHeight) {
        x = (screen.availWidth - w - 12) / 2;
        y = (screen.availHeight - h - 104) / 2;
        if (window.opera) y = 0; // Opera positioniert unter den Symbolleisten
        if (x<0 || y<0) { x=0; y=0; }
            else parameter = "width=" + w + ",height=" + h + ",";
        }
        parameter += "left=" + x + ",top=" + y;
        //parameter += ",location=no,menubar=no,toolbar=no,status=no";
        parameter += ",resizable=no,scrollbars=no";
        var gallery = window.open('gallery.php?cat=' + prmGallery,"gallery",parameter);
        if (gallery) gallery.focus();
}