function GetWindowSize() {
  var winW, winH;

  if (window.innerHeight) { // all except IE
    winW = window.innerWidth;
    winH = window.innerHeight;
  } else if (document.documentElement 
    && document.documentElement.clientHeight) {
    // IE 6 Strict Mode
    winW = document.documentElement.clientWidth; 
    winH = document.documentElement.clientHeight;
  } else if (document.body) { // other
    winW = document.body.clientWidth;
    winH = document.body.clientHeight;
  }

  return {WinW:winW, WinH:winH};
}