expand to available height

I’ll bet this have been answered, but . . . . I want to automatically expand my web app the maximum height available, but not full screen . . .

How?

You may want to have a look at http://rubberviews.com/rubberviewswe.html

Can’t purchase a product. Seems like it should be easy to get the screen resolution . . .

Not screen resolution. Browser window size. WebPage size…

so, opening the browser window to max height automatically can’t be done?

There is a fullScreen API somewhat implemented in the very latest versions of browsers but it fails in all others.

The size of the browser window is up to the user, not the code running inside it. As I recall, even with the FullScreen API it requires a user event like a mouse click to make it work.