doggy doors for Saints

[Thelma]

looking for a doggy door for my saint that will be big enough when he is full grown.  Any suggestions?  Anyone made their own? thanks in advance.   

[DixieSugarBear]

We made our own using the heavy sheet plastic from Walmarts and a simple 1x1 board. The windows in the room slide up from the bottom so I just open the window when I want them to be able to go out.  I will try to find a quick photos of it or take one. Dixie would kill herself with a standard size dog door. She love to run in and out of it.  I have to take her over and show her when I close so that she will not try and jump through the window with it closed.