Description of problem:
Editing form window does not contain any button ("X", "Close") to dispose it.

Version-Release number of selected component (if applicable):
BRMS 5.3.1 ER2, designer 2.3.1-DEV

How reproducible:
I wrote special character "&" into property Task Name. This character breaks editor for task form (bugzilla's issue 864920). There appears alert "Error initiating Form Editor : [Exception... "An invalid or illegal string was specified"  code: "12" nsresult: "0x8053000c (SyntaxError)"  location: "http://localhost:8080/designer/lib/ext-2.0.2/ext-all.js Line: 14"]"
I wrote back string "taskname" into property Task Name.

Steps to Reproduce:
1. create process (Strat->HumanTask->End)
2. set Task Name to "taskname"
3. generate task forms
4. set Task Name to "task&name"
5. focus on human task and choose icon "Edit task form"
6. dispose error alert
7. set Task Name back to "taskname" 
8. focus on human task and choose icon "Edit task form"
9. dispose window (there is just a part of content ... screenshot is attached)
10. focus on human task and choose icon "Edit task form"

  
Actual results:
Window is not able to close, there is no button to cancel it.

Expected results:
Window is able to close even if window is empty.

Additional info: