How to add onclick to FG submit input

Hi,
I was wondering how it's possible to add onlick javascript function to submit input via BE, if its possible?

Best regards.

OK, I will ask this way:
How to add "onclick" to submit button, which is part of Form generator?

I post a similar question, and nobody gave me any answer...

The only solution I found is to create a new element "submit" in wich you could define the action.

@MicoX
I didn't even try anything about his thread but you can insert extra attribute via Jquery attr()

Thanks for reply