There is a page on the site.
There is a frame on the page, it occupies 100% of the height and width. In fact, we work with the frame, and not with the window in which it is loaded.
Using JS to communicate between the page and the frame from another domain is impossible.
Everything works and the main window to us, in fact, unnecessarily.
But bad luck - you need to perform the function (send a message) in the frame by pressing ENTER.
Naturally, when you try to "press a button" located in the frame from the parent window from another domain, an error appears.
How to be?
In fact, I press Enter while in the frame, but it is still processed by the parent page.