I am a mobile phone games developer, now i want to develop a game which includes the dynamic map, but in the runtime of the game, the game always bloked,so if i wish the game is fluency, how i can do?

thanks for your reply, i have solved this question. uhnn, in the follow i will dipict my questions and solutions concretely:
device: nokia 7210 cell phone
tool: java and jcreator
aim: develop a game whose map can roll when the game is running.
that is to say, the map is big than the screen, for the flatness,
i want only part of maps which we can see on the screen was load into memory in the runtime, others is not be loaded.

ok, that is question, i have finished it!