Approval Inbox

I would like to show a Pop Up message when a manger approves the change records from Approval Inbox. The requirement is to display just one message before approving all the records.

 

I have managed to use the RAD application object.yes.no in the process "approval.approve" to display this message. but the problem is the message is displayed for every record that is being displayed. Say manager is approving 10 records all at once the emssage is being displayed for each and every record. How can i make it appear just one?