Thanks for your code, shlum.
The reason I want to remove the form from memory because to save a memory resource/space. For example, if I open 100 forms then all forms are hide after used(coz we only show 1-3 forms at a time), what happen to your memory. If I not mistaken, it will full with forms. It mean that my program/application will coz the computer working slower. That's why I think I should remove the form from memory after user used it. It mean that I call form when user need it and then remove(from memory) it after used.
That is my idea. I don't know it is right or not. maybe some one can give any idea or somthing to share with me.
Bye...........