I have a div with the id of \"secondHeader\" and I want to replace that entire div with another div with the same id of \"secondHeader\" but instead of replacing it , it jus
$.load isn't really the best choice here since that function's intended to just fill in the contents of a div, as you've seen. You can just use $.get instead and set the callback function to replace your original div, or change logged-in-content.html to exclude the div.
Also be aware that as a Javascript-based solution, if your users look at the source, they'll see that they can get access to logged-in-content.html by just typing it in their address bar if you're not securing it somehow else.