Form submission on iPad: how to indicate no server response (w/o ajax)

I’ve got a php script with signup form that submits to itself and stores user data in database. The application is being used solely on an iPad in the field.

If a user submits a form but the connection has been lost, they will wait awhile or keep hitting the submit button to get some response.

I know we could use HTML5 storage and I could’ve used ajax but … don’t want to rewrite the whole thing.

Is there a quick/dirty solution to this?

Use Javascript and AJAX like functionality.
There is the “quick” and “dirty” approach.