Q:

Can you make an AJAX call inside of another AJAX call in jquery?

Below is a jquery script I am working on, I have stripped down all the non-relevant parts of it.
You can see there is an ajax call, from the results there is an if statement, the other items our stripped out but anyways the captcha one is picked from the result of the first ajax call.  
I then need to make a second ajax call, this is where my trouble is, I get no errors but it doesn't seem to return a response on the second one, am I missing something?
<script type="text/javascript">
    $(document).ready(function() {
        // make ajax call
        var dataString = 'comment=' + comment;
        $.ajax({
            type: "POST",
            url: "process.php",
            data: dataString,
            dataType: "json",
            success: function(data) {
                //result from 1st ajax call returns "captcha"
                if (data.response === 'captcha') {
                    //a bunch of code is ran
                    ////////////////////////
                    //then...
                    $().bind('cbox_closed', function() {
                        var dataString2 = 'comment=' + comment + '&run=captchagood';

                        // our nested ajax call
                        // this is the part that is having trouble =(
                        $.ajax({
                            type: "POST",
                            url: "process.php",
                            data2: dataString2,
                            dataType: "json",
                            success: function(data2) {
                                if (data2.response === 'captchagood') {
                                    alert('test');
                                    $('div#loader').find('img.load-gif').remove();
                                    $('div#loader').append('<span class="success">Thanks for your comment!</span>');
                                    $('div#loader').hide().fadeIn('slow');
                                    $('span.limit').remove();
                                    $('div#comments').append(data);
                                    $('div#comments div.comment-unapproved:nth-child(1)').hide().slideDown('slow');
                                    $('input#submit-comment').unbind('click').click(function() {
                                        return false;
                                    });
                                    // success append the sanitized-comment to the page
                                    $('#comments').prepend(data.comment);
                                };
                                // end captcha status returned
                            }
                        });
                    });
                };
                return false;
            });
        });
    });
</script>

A:

There's nothing wrong with having an ajax call inside an ajax callback. In fact, you're not even doing that, what you're doing here is:

Ajax call
If call is successful and returns 'captcha' then bind a function to the cbox_closed event
When the cbox_closed event is triggered call the bound function which contains another ajax call

Some things to check for:
Is the sever returning successfully? (no 404, 500 error etc)
You're anticipating a json response. Does it contain data like {response:'captcha} that you're checking for?
When is the cbox_closed event triggered? Are you sure that it is happening?

A:

You've passed the 'success' callback to jQuery, but no 'error' callback. This way you're ignoring the error. Here is an example to capture the error, and optionally display it in the Firebug console.
var lastRequest = jQuery.ajax( { type:     "POST"
                               , url:      this._ajaxUrl
                               , data:     postdata
                               , dataType: "json"
                               , success:  _gotAjaxResponse
                               , error:    _gotAjaxError
                               } );

function _gotAjaxResponse( data )
{
  window.console && console.log( data );
}

function _gotAjaxError(xhr, status, error)
{
  // Show server script errors in the console.
  if( xhr.status == 500 )
  {
    var response = xhr.responseText;
    response = response.replace( /\r?\n/g, "" )
                       .replace( /(<\/)/g, "\n$1" )
                       .replace( /<[^>]+>/g, "" )
                       .replace( /^\s+/, "" )
                       .replace( /\s+$/, "" );
    window.console && console.error(response);
  }

  alert("I'm sorry...\n\n"
      + "Unfortunately an error occured while communicating with the server.\n"
      + "Please try again later.");
}

