Q: how can i fixed div something like apple's webpage how can i make fixed div somethin like this http://i.stack.imgur.com/ojANM.png
web address: http://store.apple.com/us/buy-ipad/ipad-mini-retina

A: These are so-called "sticky notes" and there are plenty of easy-to-implement plugins out there. Have a look at this: http://stickyjs.com/ 

A: You should take a look at CSS  position: fixed;
http://www.w3schools.com/cssref/pr_class_position.asp
The Javascript plugins that are available basically just add position:fixed; and something like top: 0; when you scroll down and the top of the browser window reaches that div.
