Submit form with javascript


How to automatically submit a form (e.g. with javascript) after clicking a lightbox button?

We are trying to create the “instant download” email nurturing campaign for those users who already gave us their contact details.

Use case:
Form in a lightbox, pre-filled with GET parameters. User clicks a button and the form doesn’t pops up and submits itself.

Wondering if there’s some javascript which could do that.