Can't move plz help

every time I fly up or walk for about 5 sec, even tho I stop my character keeps on moving n moving till no where to be found follow by the u have been disconnected message.

What kind of connection? Also, what does the top frame of Help > About Second Life say?

Remember, asking smart questions the first time is more likely to result in a smart answer.

http://www.catb.org/~esr/faqs/smart-questions.html

Start with resetting your modem and/or router. That is a classic symptom of loss of connection to the LL servers. Rebooting those devices often fixes it. If does not work then you will need to give some computer specs for your computer and how you connect to the internet.

No one can make much of a suggestion without some information. My suggestion is just an educated guess.