//open menu with given ID
function openMenu(id) {
  //if the menu code is ready
  if(um.ready) {
    //find co-ordinates of link object
    var linkObj = document.getElementById("button_" + id);
    var coords = {
      'x' : um.getRealPosition(linkObj,'x'),
      'y' : um.getRealPosition(linkObj,'y')
    };
    //increase y-position to place below the top of the button
    coords.y += linkObj.offsetHeight - 43;
    //increase x-position to place it below the link
    coords.x += linkObj.offsetWidth;
    //activate menu at returned co-ordinates
    um.activateMenu("menu_" + id, coords.x + 'px', coords.y + 'px');
  }
}

//close menu with given ID
function closeMenu(id) {
  //if the menu code is ready
  if(um.ready) {
    //deactive menu
    um.deactivateMenu("menu_" + id);
  }
}