Display a form within another form or panel

Thanks I think you are right and it might be the best practice to make a Control and place it on the form. However I will try your suggestion (just for training purpose) with the Control cast stuff on the form. Again thanks for your ideas.

In my own words, you have a chat client you want to reuse, and it will be on a form to the left of a splitter. Will the chat client be independent but placed inside the form, or will it act like it's part of the form? If it's the latter, create the chat client from a control instead of a form. Most of the method calls remain the same (the Form class is derived from the Control class) so it shouldn't be much of a stretch. Compile the chat client project as a class library so that you get a .dll file instead of a .exe file. Whenever you need to use it, add the dll to the project's references and you'll be able to reuse the control without copy-pasting the code. Controls can contain other controls, much in the same way a form does. The limitation on its behavior is mainly in that it can't minimize, etc. and can't be run independently. To use the chat client as a standalone if you code it as a control, you would have to create a form and add the control to the form. Since Form is derived from Control, however, you may want to try adding a Form object to another Form as a control and see what happens. If you can, that's your answer right there.

Thanks for your answer, I agree with you, but that was just an example. I will explain in another way : Think of a form which is devided by splitter. In the part n the right side I will display a form, which is a chat client (includes many controls). This chat client screen an its logic is also used in other applications. Istead of coding it all again, I think there should be a possiblity to display this chat form left to the splitter in the main form (not as MDI). Do you understand my point. My question is : Is there a way to do this and how is it done ? Thanks for your help. If this is technical not possible, how do you solve this ? Do you code (copy and paste) it every time you want to use this chat client again ? Do you make the Chat Client as a control ? if so, how is that be done ? Do you have some sort of tutorial how one can make a control based on a form ? Thanks again

In this case it would be better if you coded a Control to display the clock. That way you can treat it like any other control on your form.