function myOpenWindow(url, w, h) {
  var window_width=(screen.width)-10;
  var window_height=(screen.height)-10;
  var window_left=(screen.width-w)/2;
  var window_top=(screen.height-h)/2;
  window.open(url, "","width=" + window_width + ",height=" + window_height + ",top=" + window_top + ",left=" + window_left + ",scrollbars=1,resizeable=yes");
}