#3785 bugfix - control user if statement contents updated

[StephDriver]

problem was with forms not communicating correctly with each other. Updated with code from @ajrbyers to fix this. Tested the fix.

Closes #3785

[mauromsl]

@StephDriver : While I understand the changes, I'm struggling to grasp why it resolves the reported problem. Could you comment on how that's the case? the previous nested form had the same action as this button, with the same inputs being posted

[StephDriver]

My notes on this solution are 'paste in Andy's code'- it was an issue I spent a lot of time investigating, could replicate but couldn't quite understand why it was happening, then I pair-programmed it with Andy and I'll admit I still don't understand how or why this change solves that problem - but I ran the same tests after his changes and the problem had gone away. So over to you to explain further @ajrbyers .

[ajrbyers]

@StephDriver : While I understand the changes, I'm struggling to grasp why it resolves the reported problem. Could you comment on how that's the case? the previous nested form had the same action as this button, with the same inputs being posted

You can revert it and take a look but for some reason we couldn't get to the bottom of the first button in the list wouldn't fire the hijack process.

Anyway - nested <form> tags are not allowed in HTML5 and this does resolve the issue we saw.