var isIE = document.all ? true : false;

function showSubNav(menuID, source)
{
    var leftPos = 0;
    var leftMiddlePos = 0;
   
    var divcontainer = document.getElementById("topNav_dropdownMenuDiv");
    if (source != "null")
    {
        var submenus = divcontainer.getElementsByTagName("div");
        for (i = 0; i < submenus.length; i++) {
            submenus[i].style.display='none';
        }

        var whereIs=getElementOffsetLocation(source);
        //elementTop=whereIs[1];
        leftPos=whereIs[0];
        
        //This will help us center the menu under the parent menu item - no longer part of spec
        //leftMiddlePos = leftPos + (source.offsetWidth/2);
        
         //alert ("left Pos = " + leftPos);
          //alert ("left Middle Pos = " + leftMiddlePos);
        
    }

    var submenu;
    submenu = document.getElementById(menuID);
    //alert ("submenu = " + submenu);
    if (submenu == null)
    {
       var s;
       var submenus = document.getElementsByTagName("div");
       for (s in submenus)
       {
            //alert(submenus[s].id);
            if (submenus[s].name == menuID)
            {
                submenu = submenus[s];
                break;
            }    
       }
    }


    if (submenu != null)
    {
        submenu.style.display='block';
        if (source != "null")
        {
            var whereIsMenuStart = getElementOffsetLocation(divcontainer);
            //alert ("submenu pos = " + (leftMiddlePos - (submenu.offsetWidth/2)) + " and divcountainer pos = " + whereIsMenuStart[0]);

            //This places menu at left edge of parent menu item  
            submenu.style.left = leftPos;
          
            //This will center the menu under the parent menu item - no longer part of spec
            //if (leftMiddlePos - (submenu.offsetWidth/2) < whereIsMenuStart[0])
            //    submenu.style.left = whereIsMenuStart[0];
            //else
            //    submenu.style.left = leftMiddlePos - (submenu.offsetWidth/2);
        }
    }
}


function leaveNavButton(subMenuID, topNavItem, e)
{
    //alert ("hiding subnav");
    var menu = document.getElementById(subMenuID);
    
   if (menu == null)
   {
       var s;
       var submenus = document.getElementsByTagName("div");
       for (s in submenus)
       {
            //alert(submenus[s].id);
            if (submenus[s].name == subMenuID)
            {
                menu = submenus[s];
                break;
            }    
       }
   }

    if (menu != null)
    {
        var whereIs=getElementOffsetLocation(topNavItem);
        var top=whereIs[1];
        var left=whereIs[0];
        var right = left + topNavItem.offsetWidth;
        var bottom = top + topNavItem.offsetHeight;
        
        var eve;
        //=e||event;
        if(!e)
        { eve = window.event;}
        else
        { eve = e;}

        var mousepositions=getMousePosition(eve);
        
       //alert ("mouse position - left: " + mousepositions[0] + ", top: " + mousepositions[1] + "menu position - left: " + left + ", right: " + right + ", top: " + top + ", bottom: " + bottom );
        
        if ( mousepositions[0] < left+5  || 
             mousepositions[0] > right-5 || 
             mousepositions[1] < top + 2 
           )
        {
            menu.style.display='none';
        }
    }
}



function hideSubNav(menuID, e)
{
    //alert ("hiding subnav");
    var menu = document.getElementById(menuID);
    
   if (menu == null)
   {
       var s;
       var submenus = document.getElementsByTagName("div");
       for (s in submenus)
       {
            //alert(submenus[s].id);
            if (submenus[s].name == menuID)
            {
                menu = submenus[s];
                break;
            }    
       }
   }

    if (menu != null)
    {
        var whereIs=getElementOffsetLocation(menu);
        var top=whereIs[1];
        var left=whereIs[0];
        var right = left + menu.offsetWidth;
        var bottom = top + menu.offsetHeight;
        
        var eve;
        //=e||event;
        if(!e)
        { eve = window.event;}
        else
        { eve = e;}

        var mousepositions=getMousePosition(eve);
        
       //alert ("mouse position - left: " + mousepositions[0] + ", top: " + mousepositions[1] + "menu position - left: " + left + ", right: " + right + ", top: " + top + ", bottom: " + bottom );
        
        if ( mousepositions[0] < left+5  || 
             mousepositions[0] > right-5 || 
             mousepositions[1] < top + 2 || 
             mousepositions[1] > bottom-1 
           )
        {
            menu.style.display='none';
        }
    }
}


function getMousePosition(ev)
{
    var _x;
    var _y;
    if (!isIE) {
        _x = ev.pageX;
        _y = ev.pageY;
    }
    if (isIE) {
        _x = ev.clientX + document.body.scrollLeft;
        _y = ev.clientY + document.body.scrollTop;
    }
    posX = _x;
    posY = _y;
    var  pos=Array(posX,posY);
    return pos;
}

function giveLayout(obj)
{
    //if this is IE, and theposition of the element is relative, give it haslayout - otherwise, calculating offset location is wrong
    if (obj.currentStyle){ //do the hasLayout if it is relative
        if (obj.currentStyle.position=='relative') {
            obj.style.zoom='100%'
        }
    }
}

function getElementOffsetLocation(obj) 
{
//adapted from an example at quirksmode.org 
    giveLayout(obj);
	
    var curleft = curtop = 0;
    if (obj.offsetParent) {
        curleft = obj.offsetLeft;
        curtop = obj.offsetTop;
        while (obj = obj.offsetParent) {
            giveLayout(obj);
            curleft += obj.offsetLeft
            curtop += obj.offsetTop
        }
    }
	
    return [curleft,curtop];
}