How to use dialog boxes

Hi all,

Hope anyone can clear this up to me. Following the document:

https://it.mathworks.com/help/matlab/creating_guis/update-dialog-boxes.html

What if I want to produce a dialog box without a figure fig below?

Or just resize the figure to be the equal to the dialog box. I've tried looking at the figure properties but found nothing about the size of the window.

Thanks!