How to update a div in Rails using ajax?

Question

JavaScript

Essence: there is a page #1 with content (one line). And there is page #2 with a button (link_to). How can I make it so that on each click on the button on page #2, the content of page #1 is substituted in the div located on it?

Please, if you know, give a code example to make it clear.

Thank you.