I build JQuery/JS/PHP/mySQL app with DB records management and need to provide reliable & complete feedback to the user on AJAX calls, modifying back end DB records. The problem IMHO is `$.ajax` `success:` and `error:` functions indicate just AJAX transport layer success and not the whole process. What if DB modification fail? How can one provide the complete feedback to the user?

I ended up with 

```

$.ajax({
   url: "/action/delete",
   data: "rowid="+rowid,
   complete: function(xmlHttp) {
   if ( xmlHttp.responseText ) alert('Success - back end returned "success"');
      else alert('failure - back end returned NULL')
   }
});  

```

and PHP response:

```

$success = deleteRecord( $_GET(rowid) );

if($success) { 
   print 'success';
} else {
   print NULL; 
}
exit();

```

The idea is simple - if I manage to get positive feedback from the back end, then the whole operation succeeded, if not - user don't care where problem occurred.

Thank you in advance, your feedback is highly appreciated.