Availability Check and alternative materials

Hi,

We want to be able to offer alternative materials if the material entered is not available or only partially available. We do not use APO or GATP.

We only want to do this when the materials entered is not available, (after the availability check) and an alternative is available so the user can then decide if they want to acccept the alternative.

Is there a way to do this without resorting to user exits?

Regards