内联编辑中的POST值

I used this code from Change table cell from span to input on click- The replace one for inline edit now i want to post values through ajax and i am not sure how. I just want to post the comments the users have edited and update them on the database This is how i got so far:

$.ajax({
        type: "POST",
        url: "comments.php",//to update the comments
        data: "data"

                });

Not sure what to put next. Is it possible to post values when user click out of input area? and does the data have to be serialize?
Thanks in advance!

$.ajax({
        type: "POST",
        url: "comments.php",//to update the comments
        data: {"comments":$("yourformId").serialize()},
        success:function(res)
         {
           //Do what ever you want 
         }

           });

And in your comments.php just print_r($_POST) will give you the posted array via ajax

If you use form.serialize you will get all the data from the form you submitted