window.onload= function(){SetupHeaderMenus();} 

var HeaderMenuTimeout;
var HeaderMenuList;

function SetupHeaderMenus()
{    
    HeaderMenuList = document.getElementsByTagName("div");
    
    for (var Index in HeaderMenuList)
    {
        if (HeaderMenuList[Index].className == 'HeaderMenu')
        {
            var HeaderMenuItem = HeaderMenuList[Index];

            HeaderMenuItem.onmouseover = function(){HideHeaderMenus(); this.getElementsByTagName("div")[0].style.display='block'; clearTimeout(HeaderMenuTimeout);} 
            HeaderMenuItem.onmouseout = function(){HeaderMenuTimeout=setTimeout(HideHeaderMenus, 500);}     
        }
    }
}

function HideHeaderMenus()
{ 
    HeaderMenuList = document.getElementsByTagName("div");
       
    for (var Index in HeaderMenuList)
    {
        if (HeaderMenuList[Index].className == 'HeaderMenu')
        {
            var HeaderMenuItem = HeaderMenuList[Index];

            HeaderMenuItem.getElementsByTagName("div")[0].style.display='none';             
        }
    }
}