function showmenu(elmnt)
        {
            document.getElementById(elmnt).style.display = "block";
            document.getElementById('lnk_'+elmnt).className = "menu_on"; 		
        }
        
function hidemenu(elmnt)
        {
	        document.getElementById(elmnt).style.display = "none";
	        document.getElementById('lnk_'+elmnt).className = "menu_off";       	
        }