var Timer, lastItemId, agent, currentItemId;

function initMainMenu() {
  div = document.getElementsByTagName("div");
  for (i = 0; i < div.length; i++) {
    if (div[i].className == "MenuItemS") {
	  currentItemId = div[i].id;
	}
  }
  // browser detect
  if (navigator.vendor) {
    agent = "safari";
  } else if (window.opera) {
    agent = "opera";
  } else if (document.all) {
    agent = "ie";
  } else {
    agent = "dom";
  }
}

function $(id) {
  return document.getElementById(id);
}

function menuMouseOver(itemId) {
  clearInterval(Timer);
  showSubMenu(itemId);
}

function menuMouseOut(itemId) {
  lastItemId = itemId;
  Timer = setInterval("hideSubMenu('"+itemId+"')", 150);
}

function showSubMenu(itemId) {
  if (lastItemId && lastItemId != itemId) {
    hideSubMenu(lastItemId);
  }
  
  if ($("Sub"+itemId)) {
    //show SunMenu div
    $("Sub"+itemId).style.display = "block";
  }
}

function hideSubMenu(itemId) {
  if ($("Sub"+itemId)) {
    $("Sub"+itemId).style.display = "none";
  }
}