I need a simple piece of code/script for my website to accomplish the following:
1. A visitor comes to Landing Page A.
2. After a set period of time, a countdown timer appears telling them they have 72 hours left to to view Landing Page A.
3. After 72 hours of their first visit, they no longer can view landing Page A and are automatically re-directed to landing page B.
This project requires a really quick turnaround, and I need someone who can complete it within the next 24hours.