Oracle Forms

I want in the main window ( that is only window in the module ) press button to appear another canvas.

but that I can't make it , I just made two window until the another window appear.

that's all

I tried with :-

show_view('canvas_name');

but didn't work with me Sad

the another canvas made it stacked Canvas .... but also didn't work Sad

so please , How can I make two Canvas in one Window only ?

and thanks in advance