Why does a script stop working after executing another script?

Question

JavaScript

Good day.
There is a site: u0763918test2.isp.regruhosting.ru
When you click on the pictures in the green block, the background in the gray block changes.

But everything changes if we load the upload image and click to update the div. We add a file to the green block, everything is as it should be. But when you click on the pictures, they no longer become the background of the gray block, nothing happens at all.
How to be?

Answer 1

How to be?

Look for a problem in the code and fix it.

Answer 2

Most likely, all your images lose their click event handler.