Would would cause this?

I have a strange problem. The thing that I created works fine when I use ctrl+enter to compile it. However when I uploaded it to my server most of the things worked. But not all. Part of my project has a form on it. If a required field is left blank it outputs the error message. Now that works. But if everything checks out it sends the information to a php script and uploads it to the database, if successful it outputs the success message, if not it outputs an error. This all works fine when compiling it directly in Adobe Flash CS4. But if the form checks out it does nothing, it doesn’t output an error, it doesn’t update the database, it doesn’t do anything. What could be a cause of this?