//dropdown menu code

var hideMenuTimeout;
var lastMenuId = '';

function positionMenu(obj, menuId)
{
    //set dropdown menu position
    var menu = document.getElementById(menuId);
    menu.style.left = obj.offsetLeft + 'px';
    menu.style.top = (obj.offsetTop + obj.offsetHeight + 3) + 'px';
    
    //set menu event
    obj.onmouseout = function() { delayHideMenu(menuId) };
    
    //set dropdown menu events
    menu.onmouseover = function() { showMenu(menuId) };
    menu.onmouseout = function() { delayHideMenu(menuId) };
    
    showMenu(menuId);
}

function showMenu(menuId)
{  
    //clear hide menu timeout
    clearTimeout(hideMenuTimeout);
    
    //hide last dropdown menu shown
    if(lastMenuId.length > 0)
        document.getElementById(lastMenuId).style.visibility = 'hidden';
    
    //show dropdown menu
    var menu = document.getElementById(menuId);
    menu.style.visibility = 'visible';
    
    lastMenuId = menuId;
}

function delayHideMenu(menuId)
{
    //set menu to disappear after 250 ms
    hideMenuTimeout = setTimeout("hideMenu('" + menuId + "')", 250);
}

function hideMenu(menuId)
{
    //hide menu
    var menu = document.getElementById(menuId);
    menu.style.visibility = 'hidden';
}