Question

In fact during a JS script I change the innerHTML attribute of a DIV, and
this content itself contains JS code.

The problem: This code is not executed js on the page.

Answer 1

If you want to execute some javascript after the page loads, you need to insert it in the head of the document:

var script = document.creatElement('script');
script.src = "path to some script";
script.type = "text/javascript";
document.getElementsByTagName('head')[0].appendChild(script);

or to use eval()