var lastdiv = "";
var woher;
var globalsubnavtimeout;
  
function showDropdown (woher) {  
	 hideDropdown();
	 lastdiv = woher;
	 document.getElementById(woher).style.visibility = "visible";
}

function hideDropdown() { 
 if (lastdiv != "") { 
  document.getElementById(lastdiv).style.visibility = "hidden";     
  }
}    
 
function mainout() {
 globalsubnavtimeout = setTimeout("hideDropdown()",500);
} 

function subtimeout () {
 clearTimeout(globalsubnavtimeout);
}