Want to convert warning message in error message.

Hi..

In transaction code F-47, one warning msg has come 'Purchasing Document belongs to another supplier'.

So, now i want this should be an error msg. I checked at configuration level, but it not possible.

I got the include where this msg has come.

I searched for User Exist and BADI, but not able to find.

If any one can give me the solution for this.

Thanks in advance....!!

Thanks & Regards,

Poonam.