window.open() on a multi-monitor/dual-monitor system - where does window pop up?

Question

When using javascript window.open() on a multi-monitor system, how do you control which monitor, or where in the display space the popup opens? It seems out of control to me

Answer 1

/**
 * Display popup window in the center of the screen.
 */
function popupWindow(url, title, w, h) {
  // Use window.screenX to center the window horizontally on multi-monitor 
  // setup. 
  var left = window.screenX + (screen.width / 2) - (w / 2);
  var top = (screen.height / 2) - (h / 2);
  return window.open(url, title, 'toolbar=no, location=no, directories=no, status=no, menubar=no, scrollbars=no, resizable=yes, copyhistory=no, width=' + w + ', height=' + h + ', top=' + top + ', left=' + left);
},