How to Run An Application only if Other Application Is running

This code Demonstarte the how you can set an application running Depend on Other.
Suppose we have 2 apps app1 and app2. Now App2 run only if app1 is running. Or say App2 Needs App1 to run.
Download Source Code App2 Needs App1 to Run

 1. App1 is ruuning and Its Button call for App2

 2. App2 is Running Ok and Message shown "Its OK".

3. If any one try to run App2 directly from bin folder it shown an error message It Require App1.

Download Source Code App2 Needs App1 to Run