oracle forms - add custom procedure when user click X to close window

Hi .  I am in EBS 11.5.10.2  ( oracle forms version 6i ).   I have a custom form and hope someone can give me suggestion on how to handle it.

The custom form is very simple.  the data block is base one a VIEW ( create view as select DISTINCT xxxxxx ) with function base column ) . The form mainly have 2 functions.  Save and Find.  .. when the save icon is clicked , it will called a "custom procedure" to call EBS standard API to further process and save data into base table.  That is all good.  But when user click on X ( top right ) to close the form,   The message "do you want to save your changexxxx " pop up.  Although it return "FRM-40400: Transaction