Jquery :: Text Already In Input Fields

I have 2 input fields.
Input 1: Website URL
Input 2: Website Directory

Firstly I would like the "http://" to automatically appear in input one and two and it can't be edited or removed. Then whatever is typed in input one, I would like it to automatically copy into input 2, and the user can't delete whats in input 2 without going through input 1. Then lastly the user can add data into input 2, without input 1 changing.

Here is an example:
Red = Can't be deleted Green = Can be changed Blue = additional text to input 2
Input 1: http://www.yourwebsite.com/
Input 2: http://www.yourwebsite.com/extra/directory
How to do this?