function subwin(xURL, xName, W, H)
{
    var sX = (self.screen.width -  W)/2;
    var sY = (self.screen.height - H)/2;
    if (sX < 0) { sX = 0; }
    if (sY < 0) { sY = 0; }
    window.open(xURL, xName, "resizable=0,menubar=0,scrollbars=yes,width=" + W + ",height=" + H + ",dependent=no,alwaysRaised=yes,left=" + sX + ",screenX=" + sX + ",top=" + sY + ",screenY=" + sY);
    return false;
}