var old_menu = ''; 
var old_cell = ''; 
function menuclick( submenu ,cellbar) 
{ 
if( old_menu != submenu ){ 
if( old_menu !='' ){ 
old_menu.style.display = 'none'; 
old_cell.src= 'images/godown.gif'; 
} 
submenu.style.display = 'block'; 
cellbar.src = 'images/goup.gif'; 
old_menu = submenu; 
old_cell = cellbar; 

}else{ 
submenu.style.display = 'none'; 
cellbar.src= 'images/godown.gif'; 
old_menu = ''; 
old_cell = ''; 
} 
}