>Just deactivating window
>by mouse click elsewhere. I want to prevent this behavior.

Hi Vlad,

What I do in such situations, when I want to prevent users from clicking
anywhere and still be able to click on toolbar.
I add programmatically a transparent container to the form, which covers ewerything I don't want the user to click on. (or, add it to the form through Form Designer, send it to back, and then just bring this container
in front of the form by thisform.MyContainer.ZOrder(0).
You may put your lookup grid into that container.

Nick