BlackBerry Application

I am looking to build a simple Blackberry solution requiring two screens. Shows list of accounts: (Personal, Business, Credit Card)? ? and button to ‘Get Accessible Accounts’. Clicking the button will bring a screen, to supply? user credential -? username and password followed by OK. This will negotiate with account server (could be application server) once credential are verify the account will be provided which will be refreshed to mobile screen. Make sure that these get cleared when the screen to put to sleep. So whenever you start the mobile device it would have any account cached, only after get accessible account you need to get the account and will be maintained until the screen go to sleep mode (auto or forced)