Need Help with Prepend!!!

Need Help with Prepend!!!

below i am using this code to bring back chat posts from the database... i am prepending the result to a table... but what i want to do is make every other TR a different bg colour.

so like this

<tr class="second">NEWER POST</tr>
<tr class="first">First Post</tr>

because i am using prepend to put the latest record at the top of the table... im not sure how to add the class to each tr


function Get_Message() {
if(!locked){
$.ajax({
type: "GET",
url: "action/getmessages.php",
beforeSend: function(){
    // Handle the beforeSend event
    locked = true;
},
success: function(data){
      
      $('table.shoutbox').prepend(data);
      if(data != '') {
      PlaySound();
      }
      locked = false;
   
}
});
}
}
[/code]