function switchMenu(curr_id, total_num) {    
 for(var i=0; i<total_num; i++)     {    
         //debugger;                     
     var el = document.getElementById('menu_sub_'+i);  
     if(!el) return;        
     var img = document.getElementById('menu_master_'+i); 
     if(i == curr_id) {   
          el.style.display = "block";      
          img.src = "images/hotmenu_"+(i+1)+"a.jpg"; 
                                                                          
      } else{            
          el.style.display = "none";
          img.src = "images/hotmenu"+(i+1)+".jpg";
     } 
  } 
}