David,

I tested my form again and again and found new problems:
First of all, I don't know what event occurs when a user clicks on close button of the form (I mean the close button on the right upper cooner of the form). I tried Destroy, Unload, other - all unsuccessfully. If I close my forms using special close buttons "Cancel" (thisform.hide()) all work, but if I close my form using the right cooner close button, my form unloads (I mean my second form, which I want just hide not unload):(.

The second problem that I discovered is that sometimes (I have not catched the sequence of clicking yet) when I released my form I had an error message: "Can not access selected table". Now I place tableupdate() into unload method of my form (it was before in release method) and I don't see this error. But I am not sure that this is a solution.

Thanks in advance