function findPosX(obj)
    {
    	var curleft = 0;
    	if (obj.offsetParent)
    	{
    		while (obj.offsetParent)
    		{
    			curleft += obj.offsetLeft
    			obj = obj.offsetParent;
    		}
    	}
    	else if (obj.x)
    		curleft += obj.x;
    	return curleft;
    }

    function findPosY(obj)
    {
    	var curtop = 0;
    	if (obj.offsetParent)
    	{
    		while (obj.offsetParent)
    		{
    			curtop += obj.offsetTop
    			obj = obj.offsetParent;
    		}
    	}
    	else if (obj.y)
    		curtop += obj.y;
    	return curtop;
    }

		function turnOffAllLayers()
    {
    
    	document.getElementById('topNav1_dropdown').style.display="none";
    	document.getElementById('topNav2_dropdown').style.display="none";
    	document.getElementById('topNav3_dropdown').style.display="none";
    	document.getElementById('topNav4_dropdown').style.display="none";
    	document.getElementById('topNav5_dropdown').style.display="none";
    }
		
    function topNavDropDown(topNavDivName,dropDownDivName)
    {
    	turnOffAllLayers();
    	topNavDiv=document.getElementById(topNavDivName);
    	dropDownDiv=document.getElementById(dropDownDivName);
    	dropDownDiv.style.top=(15+findPosY(topNavDiv)*1)+"px";
    	dropDownDiv.style.left=findPosX(topNavDiv)+"px";
    	if(dropDownDiv.style.display=="none")
    		dropDownDiv.style.display="block";
    	else
    		dropDownDiv.style.display="none";
    }