function align_bottom(layer_name)
 {
 //window.alert(align_bottom.caller);
  sh=bmenu.clientHeight;
  sw=bmenu.clientWidth;
  layerObject(layer_name).top=iBody.scrollTop+iBody.clientHeight-sh;
  layerObject(layer_name).left=(iBody.clientWidth-sw)/2;
  showLayer(layer_name);
 }