Error handling and user notification in 3-tier architecture

Hi,
I am workin' on a application with three tier architecture. We have used VC++,C++,OLE, and stuff to bring up the application.Now,Have a small problem as under:
For all the user notifications/Error handling from the server,we send strings thru the communication channels to the frontend.Now, in the front end we check what string we have recieved and process accordingly.For this we had to put all the valid strings in a common header file and include it both in the frontend and the backend.This essentially henders the 3-tier architecture.
How best it can be modified such that we can remove that common header file.

Thanx in advance,
Leonn.

Hi...instead of passing strings from the backend to the frontend, u can pass ur own defined error codes. For this a mapping table needs to be there at the front end which maps all the error codes to the respective strings to be displayed. There is no need of a mapping table at the backend. By introducing error codes ur architecture will become more extensible so that in future if u want to add some new error code, it can be done with no changes in the frontend if ur maintaining the mapping table in a flat file...Hope this answers ur query...

Hi LittleMutex,
Thanx man.I shall implement the same in couple of days time.My hard disk crashed.I have lost all the recent work (Not the whole application though)inspite of clear case.......

neway,Thanx alot again.I shall do that.

Leonn.