It’s been awhile. Recently I’ve been too busy building a big DNN website which I wanted to have the JS and CSS injected into header section of the page and most importantly, after Jqeury.js.
Most of the scripts you can find it in Google are no longer valid and it will return nothing but tons of errors codes. Until I found this blog post: Injecting Injecting CSS / Javascript on your page, revised by Sotiris Filippidis. So go ahead and check him out.