Window.onload Not Working On Page Being Loaded Into Base Page

So there is an index.html page, and a navbar.html page. navbar.html gets loaded into the index.html page

 $(".include-nav-bar").load("share/navbar.html");

window.onload works fine on the base page (index.html), but, randomly works on the loaded in page (Note, I don't have onload on the base page, I only have onload on the navbar.html page)

The onload inside the navbar page randomly works after maybe the 3rd reload, I suspect its because the base page is overriding it or something.

Is there a way to get that second onload to work inside the loaded Index page? (Correctly any way, and not randomly)

Try $( document ).ready() function.

Code included inside $( document ).ready() will only run once the page Document Object Model (DOM) is ready for JavaScript code to execute. Code included inside $( window ).on( "load", function() { ... }) will run once the entire page (images or iframes), not just the DOM, is ready.

Here is the documentation. https://learn.jquery.com/using-jquery-core/document-ready/