var activeButton = null;

// Capture mouse clicks on the page so any active button can be
// deactivated.

if (browser.isIE)
  document.onmousedown = pageMousedown;
else
  document.addEventListener("mousedown", pageMousedown, true);

function pageMousedown(event) {

  var el;

  // If there is no active button, exit.

  if (activeButton == null)
    return;

  // Find the element that was clicked on.

  if (browser.isIE)
    el = window.event.srcElement;
  else
    el = (event.target.tagName ? event.target : event.target.parentNode);

  // If the active button was clicked on, exit.

  if (el == activeButton)
    return;

  // If the element is not part of a menu, reset and clear the active
  // button.

  if (getContainerWith(el, "DIV", "menu") == null) {
    resetButton(activeButton);
    activeButton = null;
  }
}


function buttonClick(event, menuId) {

  var button;

  // Get the target button element.

  if (browser.isIE)
    button = window.event.srcElement;
  else
    button = event.currentTarget;
	
  // Blur focus from the link to remove that annoying outline.
  button.blur();

  // Associate the named menu to this button if not already done.
  // Additionally, initialize menu display.

  if (button.menu == null) {
    button.menu = document.getElementById(menuId);
    if (button.menu.isInitialized == null)
      menuInit(button.menu);
  }

  // Reset the currently active button, if any.

  if (activeButton != null)
    resetButton(activeButton);
	
  // Activate this button, unless it was the currently active one.

  if (button != activeButton) {
    depressButton(button);
    activeButton = button;
  }
  else
    activeButton = null;

  return false;
}


function depressButton(button) {

  var x, y;

  // Update the button's style class to make it look like it's
  // depressed.

  button.className += " menuButtonActive";

  // Position the associated drop down menu under the button and
  // show it.

  x = getPageOffsetLeft(button);
  y = getPageOffsetTop(button) + button.offsetHeight;

  button.menu.style.left = x + "px";
  button.menu.style.top  = y + "px";
  button.menu.style.visibility = "visible";
}


function resetButton(button) {

  // Restore the button's style class.

  removeClassName(button, "menuButtonActive");

  // Hide the button's menu, first closing any sub menus.

  if (button.menu != null) {
    closeSubMenu(button.menu);
    button.menu.style.visibility = "hidden";
  }
}

function buttonMouseover(event, menuId) {

  var button;

  // Find the target button element.

  if (browser.isIE)
    button = window.event.srcElement;
  else
    button = event.currentTarget;

  // If any other button menu is active, make this one active instead.

  if (activeButton != null && activeButton != button)
    buttonClick(event, menuId);
	
  return false;
}


function closeSubMenu(menu) {

  if (menu == null || menu.activeItem == null)
    return;

  // Recursively close any sub menus.

  if (menu.activeItem.subMenu != null) {
    closeSubMenu(menu.activeItem.subMenu);
    menu.activeItem.subMenu.style.visibility = "hidden";
    menu.activeItem.subMenu = null;
  }
  removeClassName(menu.activeItem, "menuItemHighlight");
  menu.activeItem = null;
}

function menuItemMouseover(event, menuId) {

  var item, menu, x, y;

  // Find the target item element and its parent menu element.

  if (browser.isIE)
    item = getContainerWith(window.event.srcElement, "A", "menuItem");
  else
    item = event.currentTarget;
  menu = getContainerWith(item, "DIV", "menu");

  // Close any active sub menu and mark this one as active.
  if (menu.activeItem != null)
    closeSubMenu(menu);
  menu.activeItem = item;

  // Highlight the item element.
  item.className += " menuItemHighlight";
  
  // Initialize the sub menu, if not already done.

  if (item.subMenu == null) {
    item.subMenu = document.getElementById(menuId);
    if (item.subMenu.isInitialized == null)
      menuInit(item.subMenu);
  }

  // Get position for submenu based on the menu item.
  x = getPageOffsetLeft(item) + item.offsetWidth;
  y = getPageOffsetTop(item);

   // Adjust position to fit in view.

  var maxX, maxY;

  if (browser.isIE) {
    maxX =
      (document.documentElement.scrollLeft   != 0 ?
         document.documentElement.scrollLeft
       : document.body.scrollLeft)
    + (document.documentElement.clientWidth  != 0 ?
       document.documentElement.clientWidth
       : document.body.clientWidth);
    maxY =
      (document.documentElement.scrollTop    != 0 ?
       document.documentElement.scrollTop
       : document.body.scrollTop)
    + (document.documentElement.clientHeight != 0 ?
       document.documentElement.clientHeight
       : document.body.clientHeight);
  }
  if (browser.isOP) {
    maxX = document.documentElement.scrollLeft + window.innerWidth;
    maxY = document.documentElement.scrollTop  + window.innerHeight;
  }
  if (browser.isNS) {
    maxX = window.scrollX + window.innerWidth;
    maxY = window.scrollY + window.innerHeight;
  }
  maxX -= item.subMenu.offsetWidth;
  maxY -= item.subMenu.offsetHeight;

  if (x > maxX)
    x = Math.max(0, x - item.offsetWidth - item.subMenu.offsetWidth
      + (menu.offsetWidth - item.offsetWidth));
  y = Math.max(0, Math.min(y, maxY));

  // Position and show it.
  item.subMenu.style.left = x + "px";
  item.subMenu.style.top  = y + "px";
  item.subMenu.style.visibility = "visible";

   // Stop the event from bubbling.

  if (browser.isIE)
    window.event.cancelBubble = true;
  else
    event.stopPropagation();

}

function menuMouseover(event) {

  var menu;

  // Find the target menu element.

  if (browser.isIE)
    menu = getContainerWith(window.event.srcElement, "DIV", "menu");
  else
    menu = event.currentTarget;

  // Close any active sub menu.

  if (menu.activeItem != null)
    closeSubMenu(menu);
}

  
function menuInit(menu) {

  var itemList, spanList;
  var textEl, arrowEl;
  var itemWidth;
  var w, dw;
  var i, j;

  // For IE, replace arrow characters.

  if (browser.isIE) {
    menu.style.lineHeight = "2.5ex";
    spanList = menu.getElementsByTagName("SPAN");
    for (i = 0; i < spanList.length; i++)
      if (hasClassName(spanList[i], "menuItemArrow")) {
        spanList[i].style.fontFamily = "Webdings";
        spanList[i].firstChild.nodeValue = "4";
      }
  }
  
  // Find the width of a menu item.
  itemList = menu.getElementsByTagName("A");
  if (itemList.length > 0)
    itemWidth = itemList[0].offsetWidth;
  else
    return;
	
  // For items with arrows, add padding to item text to make the
  // arrows flush right.
  for (i = 0; i < itemList.length; i++) {
    spanList = itemList[i].getElementsByTagName("SPAN");
    textEl  = null;
    arrowEl = null;
    for (j = 0; j < spanList.length; j++) {
      if (hasClassName(spanList[j], "menuItemText"))
        textEl = spanList[j];
      if (hasClassName(spanList[j], "menuItemArrow"))
        arrowEl = spanList[j];
    }
    if (textEl != null && arrowEl != null) {
      textEl.style.paddingRight = (itemWidth 
        - (textEl.offsetWidth + arrowEl.offsetWidth)) + "px";
      // For Opera, remove the negative right margin to fix a display bug.
      if (browser.isOP)
        arrowEl.style.marginRight = "0px";
    }
  }
  
  // Fix IE hover problem by setting an explicit width on first item of
  // the menu.

  if (browser.isIE) {
    w = itemList[0].offsetWidth;
    itemList[0].style.width = w + "px";
    dw = itemList[0].offsetWidth - w;
    w -= dw;
    itemList[0].style.width = w + "px";
  }
}