GURU HELP: session_unset

http://www.CollegeSherbrooke.qc.ca/~languesmodernes/course/test_session.phps I'm trying to "session_unset()" - it worked I thought. session_unset("postcard"); unset($postcard); unset($MyImage); Go to: http://www.CollegeSherbrooke.qc.ca/~languesmodernes/course/test_session.php and "click me". It sets a session, displays an image, and then is supposed to destroy itself so that when I go back to http://www.CollegeSherbrooke.qc.ca/~languesmodernes/course/test_session.php (and or reload http://www.CollegeSherbrooke.qc.ca/~languesmodernes/course/test_session.php) I should see the text/html header and not an image/png header. The only way to right myself is to exit Netscape altogether. I have tried session_destroy() session_unregister and even session_write_close - not that any of those worked. I consulted the online manual and thought this would be enough: session_unset("postcard"); unset($postcard); unset($MyImage); I have even used the echo on line 3 to prove to myself that my session terminated itself. I believe the session terminates, but for what ever reason, http://www.CollegeSherbrooke.qc.ca/~languesmodernes/course/test_session.php is still receiving header("Content-type: image/png") and not header("Content-type: text/html") Can someone help? John (Post & reply would be helpful please.)