Michel,
You can generate a user-defined error with a customized error message like this:

ERROR "This is a customized error message"
?MESSAGE()

Note that this generates error 1098

HTH
>I think I remember having seen that before. On specific occasions, I want to force Visual FoxPro to generate an error. Howeer, MESSAGE() is not initialized in that case as it's done manually. How can I store a message in MESSAGE() when doing that?