jQuery(document).ready(function() {

  jQuery(".content").hide();
  //toggle the componenet with class msg_body
  jQuery(".heading").click(function()
  {
    jQuery(this).next(".content").slideToggle(500);
  });
});
/*
$(document).ready(function()
{
  //hide the all of the element with class msg_body
  $(".content").hide();
  //toggle the componenet with class msg_body
  $(".heading").click(function()
  {
    $(this).next(".content").slideToggle(600);
  });
});
*/