Form Validation - triggering a spinner

[hdouglas]

I have a custom component with a form, some of the fields require validation which is handled via the inbuilt Joomla form validation. On submission the form does a lot of processing including creating a large PDF file which takes a few seconds to complete before the response and redirection of the page.

On clicking the submit button I show a spinner which blocks out the elements on the page and indicates to the user something is happening.

However, if the form does not validate, I need to clear the spinner.
Is there an easy way to determin the result of the validation in javascript so the spinner can be removed.

[hdouglas]

anyone any ideas on this?