The Form Type (Magic xpa 4.x)

To create a Rich Client frame, you first need to choose Rich Client Frames as the Interface Type for your form.

Now, when you open up the form, you will see a Frames palette. You can choose the format you want to use by clicking on it. Here, the frameset is two vertical frames.

Note that these frames can also be nested, so there are many more than 6 possible combinations at runtime.