Obtain the reference of the previous window (Windows. opener)

Window. Opener usage
In a textbox with the ID "name" on window. Opener worker, you can write it:

Optional values opener.doc ument. getelementbyid ("name"). value = "input data ";

I have no good understanding of window. opener in JavaScript.
Why is it unavailable in the framework, and the pop-up window's parent window cannot be on a page in the framework? Then how can I use the pop-up window to operate the parent window in the framework?

Opener.parent.frames{'framename'}.doc ument. All. input1.value try this