function expandwindow() {
  top.window.moveTo(0,0);
  if (document.all) {
    top.window.resizeTo(screen.availWidth,screen.availHeight);
  } else {
    if (document.layers||document.getElementById) {
      if (top.window.outerHeight<screen.availHeight||top.window.outerWidth>screen.availWidth) {
         top.window.outerHeight = screen.availHeight;
         top.window.outerWidth = screen.availWidth;
      }
    }
  }
}