Change variable visibility after .load is loaded?

Question

AJAX

There is an application. Each page requires certain functions to be performed on it that do not need to be performed on the rest.
At the beginning of the site code, then somewhere in the center of the page, other pages are loaded. Inside this loaded page, we have set startIndex = true; At the end of the template, all JS libraries are included. Including app.js. In this app.Js there is a condition that if startIndex is TRUE we execute the code. But due to the fact that this startIndex is set in the document loaded by Ajax, app.js does not react to the change in any way. What to do ? killed as always 3 days, maybe a trifle I do not know but I can not solve this issue.
var startIndex = false;
$("#wrapper").load(url)