There is one onbard CALLBACK with VFP 6, (i thinks its a call back): COMRETURNERROR()

>>>That's not quite how a call back works, nor does it accomplish the same thing. There are many methods for a server process to determine what code the client runs, but allowing the server process to actually invoke the routine is what's needed. Your code sample simply invokes a synchronous method in the server and uses the return value to decide which procedure to call, but does nothing to determine when it should run.
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>>A call back works more like ON ERROR (i guess).
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>Hmm, I don't see the similarity...
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>>Larry forwarded a URL to VFPCOM - I'll check that guy out. Thats what we need, an ON EVENT service!!
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>Yeah, we're getting native event binding in VFP7 with the EventHandler function.