Assigning reserved IP for Amazon EC2 instance

view story

http://serverfault.com – I want to assign a reserved IP for an instance on EC2 so that I can use it in my configuration files. I associated an elastic IP with that instance but it changed when I stopped the instance. I have to setup application which depends on IP of instance, if IP changes, my application will fail to work. Please suggest a way so that the IP remains associated with instance permanently. (HowTos)