var lastMenu = '';

function initializeMenu() { return; }

function toggle_menu(menu_id) {
     var my_node = eval("document.all['" + menu_id + "'].style");
     if (my_node.display == "block") {
          my_node.display = "none";
	  lastMenu = ''
     } else {
          if(lastMenu != '') {
	  	toggle_menu(lastMenu);
	  }
          my_node.display = "block";
	  lastMenu = menu_id;
     }
}