Am working on an Adobe AIR application.See i have two type of users in my application ,"nurses and patients".I jus create the UI ie,both of them have a login and register pages..when both of them get logged in they have there own home pages..In their home page they have a buttons "compose new message"..both of them could send messages between them.wen patient send a message,nurse will get an alert about that message(i mean alert inside the app..not like SMS).Actually..this is a mobile application ie mobile to mobile transactions are goin to happen..
THis application is goin to run on smartphones..

My question is:

1.How can i do this messaging part?Am new to AIR applications..so i have no idea about this..please help anybody..