>I need to know how VFP50 handles local vs private memory variables. Do you have to expicitely release them to free up the memory before the routine goes out of scope ?

No. Local and private variables are automatically released when a procedure/function returns.

> I have a rather complicated function that handles incoming DDE messages. Over the course of several hours its buiding up the amount of user allocated memory (returned by SYS(1016). I've declared all the variables as local and am explicitly releasing them each time after the routine runs. Dos VFP not free up memory when running SQL queries or something like that ?

FPW 2.6 has big problems with the memory management and usually you end up because of the "Not enough memory".

VFP makes a much better memory management, but it still has problems and sometimes the available memory goes down slowly.

>I've tried stepping through the code and watching the sys(1016) value on each line but it tends to vary wildly.

Don't do it! :) You'll be surprised! :) But since you already did it... :)

Vlad