Created attachment 834626 [details]
When change parent note for plan with a nonexistent plan id, the submit btn in the warning form has no effect

Description of problem:
As subject.

Version-Release number of selected component (if applicable):
3.8.5

How reproducible:
100%

Steps to Reproduce:
1. Enter a plan page, then enter tree view tab. 
2. Click change parent node for current plan.
3. Input a nonexistent plan id, like:12345678.
4. Check the warning form.

Actual results:
System give the warning: The plan you specific does not exist in database.
The warning form has submit btn, click it, system has no action.

Expected results:
System give the warning: The plan you specific does not exist in database.
The warning form has not submit btn.

Additional info: