var menuold="";

function exDiv(navitem) 
{

  if ( document.getElementById(navitem).style.display == "none" )
  	document.getElementById(navitem).style.display = "";
  else
  	document.getElementById(navitem).style.display = "none";
	
  if ( menuold != "" && menuold != navitem )
  	document.getElementById(menuold).style.display = "none";
	
  menuold = navitem;
  
}