Question : session tracking  on wap  using php

working on session tracking  on wap . we are using php .
the problem i am facing is that the session expires when i move to the next page . The session lives on the page it is created . i have used session_Start() ,session_register() ,session_is_registered() php session function .
is there is a workaround method . jsp provides url rewriting (request.urlencode()) . can i do url rewriting in php . if yes how .
any comment will be appreciated.

thanx

Answer : session tracking  on wap  using php

I gave the reason why sessions are not preserved on wap devices..