How to remove the warning "do you want to save changes to investigation.pdf before closing"

[Harshit Bapna]

Issue: To remove the warning "do you want to save changes to investigation.pdf before closing"

I have created a XFA pdf file(using LC Designer 8.2) to display this issue

Steps to get the warning:
1) Open the attached pdf using Acrobat Professional.
2) Click the Confirm Enrollment" button
3) Now close the document & the acrobat gives a warning "do you want to save changes to investigation.pdf before closing"

Summary of the XFA pdf:
It has two text fileds. On docReady event field A is made vsisble & field B is made invisible.
On button click event the field A is made invisisble & field B is made visible.
On closing the pdf it should not throw this warning message.
 
My Efforts:
1) Found a property in adobe js docs.
           event.target.dirty=false;
It doesn't solve the problem.
2) I tried to put this logic in almost all the events listed in designer but I am not able to resolve the issue.

Please help me resolve this issue.


-- Harshit Bapna