PHP session_id() not accepting existing session id

[elishisdimedy]

I'm having trouble forcing sessions to restart in PHP. Here's the problem:I can get my session id with \[code\]session_id()\[/code\], copy it, and add to the very top of my script:\[code\]session_id('the_session_id');session_start();\[/code\]And when I open a new browser, the session from the other browser is not carried over. What settings can I check?