var preUlElement = "";
function toggle(id)
{
	ul = "ul_" + id;   
    ulElement = document.getElementById(ul);
	
	if(preUlElement != "")
		if(preUlElement != ulElement)			
   		preUlElement.className = 'closed';
	
    if (ulElement)
	{
		if (ulElement.className == 'closed')
			ulElement.className = "open";
		else
			ulElement.className = "open";
	}
	preUlElement = ulElement;
}