>Can you be more specific? Isn't in a Foundation Read system, only one window is activate and only one system memory allocated, however, in read events, each window allocate memory resources. In a read event system, the more windows that they are opened, the more heavily they task the system (I thought).?!

The foundation read was the way to go before Visual FoxPro 3. It was mostly consisting of letting ghost window on the screen given the user the impression that it was waiting for a focus to proceed but in reality the screen was loaded again but with the same status as it was before.

Using READ EVENTS will still give you the possibility of controling how many windows you want at the same time if you want to be sure your users won't run out of memory.

The simpliest way will be to have all the forms modals. Another way will be to count the number of forms on the screen and fix a limit.

But your users will probably be unhappy because in others softwares they can open multiple windows at the same time.