var menu;
 
function register (img) {
  if (img.addEventListener) {
    img.addEventListener("mouseover", show_menu, false);
    img.addEventListener("mouseout", hide_menu, false);
  }
}

function show_menu(event) {
  if (event) {
    menu.pos['block_left'][0] = event.pageX;
  }
  else if (window.event) {
    menu.pos['block_left'][0] = window.event.clientX;
  }
  menu.onmouseover(0);
}

function hide_menu(event) {
  menu.onmouseout(0);
}

function set_menu(m) {
  menu = m;
}