requested enter data when close a data add form

[newaccess]

I use form wizard to auto generated a form to add data form.
When user opne a form with default value assigned. But if user does not like tot enter data and
want to close form. access 2007 display message:

ODBC-call failed
Microsoft[ODBC driver for Oracle][oracle]ora-01400 can not insert null into ("test"."test_name")(#1400)

This issue resulted form oracle linked table test_name is not allow now.
Do we have any way to close form with this message appears?

Thanks
new access

 

[newaccess]

Thanks for forum expert suggestion. I just use command to close form without save.
UNDO or CANCEL button does not working in my case.