In Room properties you must click on "Views" and activate "enable use of views" and "visible when room starts" This second option si only for the view you selected (view 0, view 1, view 2...) use only one of them.
Ten in "view in room" you have to write the dimensions in the rules.
Finaly in "port to screen" write the window size. Use proportional numbers.
use "W" and "H". I recomend you stay "x" and "y" in 0
I hope it help you :) Good luck