function openWindow(filename, w, h, resize, winname) {
    var nWidth;
    var nHeigth;

    if (filename.match(/\?/)) {
       filename += '&'+Math.random();
    } else {
       filename += '?'+Math.random();
    }

    if (w) nWidth = w; else nWidth = 700;
    if (h) nHeigth = h; else nHeigth = 500;


	var left 	= ( window.screen.width	 - nWidth)/2;
	var top 	= ( window.screen.height - nHeigth)/2;


    if (!winname) winname = "_blank";
    if (!resize)  resize  = "no";

    var desktop = window.open(filename, winname, "width="+nWidth+", height="+nHeigth+", left="+left+", top="+top+", toolbar=no, location=no, status=no, menubar=no, scrollbars=yes, resizable="+resize);
}