active_menu =0;            
active_empty=0;  
empty_over=0;  
over_menu=0;    
off_delay = 500; // in milliseconds
                 

                 
function openMenu(menu_id){
	if (menu_id==0) return;
	if (active_menu !=0  && active_menu != menu_id)             
	{             
		OldDiv = document.getElementById("menu_" + active_menu);
		imgOff("nav"+active_menu);
		OldDiv.style.display = "none";
		active_menu =0;
	}
	imgOn("nav"+menu_id);            
	blockDiv = document.getElementById("menu_" + menu_id);
	if(blockDiv){
		blockDiv.style.display = "block";
		over_menu=menu_id;
		active_menu =menu_id;
	}
	if (menu_id != active_empty && active_empty !=0)
		imgOff("nav"+active_empty);
	active_empty=menu_id;           
	empty_over=menu_id;                 
}
                 
function outMenu(menu_id){
	setTimeout("hideMenu("+menu_id+")",off_delay);
	over_menu =0;
	empty_over=0;
}
                 
function hideMenu(menu_id){
	blockDiv = document.getElementById("menu_" + menu_id);
	if(!blockDiv)// only empty menus
	{
		if (menu_id != empty_over)            
			imgOff("nav"+menu_id);
                 
	}           
	if ((active_menu ==menu_id) && (over_menu !=menu_id))            
	{
		//imgOff("nav"+menu_id);            
		Div = document.getElementById("menu_" + menu_id);
		Div.style.display = "none";
		imgOff("nav"+menu_id);
		active_menu=0;
	}
}
                             
function imgOn(imgName) {
    //newImg = eval(imgName + "on");
    //if (newImg && document.images) document[imgName].src = newImg.src;
}
   
function imgOff(imgName) {
    //newImg = eval(imgName + "on");
	//if (newImg && document.images) document[imgName].src = newImg.src;
}