Plz help w/ global variables

To test global variables, I wrote the following PHP script: (1)<?php (2)session_start(); (3)session_register("counter"); (4)$counter++; (5)echo "$counter"; (6)// header ("location:statistics/contents.php"); (7)?> When the script is called several times, the variable is increased accordingly. Thus, it exists globally. But when I un-comment line (6), the Web page ("contents.php) is displayed but I cannot echo the variable. Why? Thanks! Tony PS: Richard, thank you for your reply, but I still don't understand why is not passed.