You can pass data to your flex application using request
parameters. The data that you pass can then be retrieved from the
Application.application.parameters object.
If you pass in an request parameter called "id" to your
application like so
http://someserver.com/myapp.mxml?id=fooYou could have some code in your application that assigns the
value to a variable like this
var id:String = Application.application.parameters.id;
Hope that helps.