SharePoint Designer Gotcha: Where's the "action" in my Form Action button?
It seemed simple enough.
I built a custom New Item form. Naturally, it needed to redirect to another page after completion. Normally for a "return page" function, a "Source" parameter in the querystring will suffice, but that didn't seem to work here. I found the Form Action Button (under Insert->SharePoint Controls->More SharePoint Controls), added Commit and Redirect actions, told it what page to use, and presto!
In fact, it didn't even try to submit the form.
Your actions may be slightly different, but that's the basic idea. All you need to do is to cut/paste this bit into your *actual* button -- or any other control, really -- and you'll have the behavior you expected in the first place.