$(document).ready(function()
{
  //hide the all of the element with class msg_body
  $(".menu_body").hide();
  //toggle the componenet with class msg_body
  $(".menu_head").click(function()
  {
    $(this).next(".menu_body").slideToggle(200);
  });
  
  // open top menu as default
  //$(".menu_body:first").show();
    
});