I'm running into an interesting problem with a prototype I want to make. Basically, I have a top nav (white), and then a sub nav (black). The sub nav is halfway down the page. What I want to happen is that once the black subnav hits the white main nav, it becomes fixed. Would I solve this with some type of if/then statement? Something like if the sub nav is at a certain y position, it's superlayer is removed and it's y position changes/becomes fixed?