How do I make the "Check Button" in CJ40 mandatory

Hi

Through poor business process, the overall field in CJ40 is constantly less then the total of year for cost planning (structural). The business has tried to reverse this trend, but the user issues still persist. The business solution is to make the check button mandatory or automatic, so the user get the message but still can override this.

Does anyone have experience in this or know which exit to use

Your help is gratefully appreciated

Thanks

Trish