function openWindow(page, width, height)
{
    var left = (screen.width-width)/2;
    var top = (screen.height-height)/2;

    var sFeatures= "top="+top+", left="+left+", width="+width+", height="+height+", "
	    + "toolbar=no, menubar=no, location=no, directories=no, resizable=no, scrollbars=yes";
    var oNewWindow = window.open(page, "", sFeatures, true);
}