I'm new to Flex 2.0 so please help me out.

I'm trying to build a simple flex application which excepts user&pass
which is then send via <mx:httpservice> to my php script. If the login
is OK, then the flex application receives a XML file which states that
the user&pass is correct. Now I have to build a checking
mechanism,which will check if the user can be logged in or not. If yes,
then it should be forwarded to another screen. Please help me out.
Thank you.