I just want to add an anchor ID to the URL so it will reload back to the form area on the page.

I solved this for successful submissions.

UserDefinedForm.php line 856:
return $this->redirect($this->Link() . 'finished' . $referrer . '#singleColumn');

But for forms with errors (blank required fields), I can't get it working.

line 718

if(Session::get("FormInfo.{$form->FormName()}.errors")){
			Controller::curr()->redirectBack();
			return;
		}

No matter what I change redirectBack(); too, nothing changes.

Did you ever find a solution? I'm working on a similar scenario where I need to control where the user ends up. Thanks!

I did but I can't remember to be honest. It was a long time ago and we've since updated the code and there wasn't a need for it anymore.

But search UserDefinedForm.php for the line return $this->redirect($this->Link() . 'finished' . $referrer and change it to what you need as that's where the redirect happens.

Liam - Thank you for your reply anyway! I did find that line of code but my situation is kind of complex. I posted a new thread about it here: http://www.silverstripe.org/all-other-modules/show/25151#post324521

Hopefully I'll find some sort of solution.

Thanks!