Coding Problem:Session Variables

[bostonmacosx]

Ok I though I understood a hint which was on here which I read but i'm still unable to change a session variable with a form submission. I would really like to know how to do this. So here are the simple pages i have.

Page1

<?

print("<FORM ACTION=createcookie2.php method=POST>");
print("<INPUT TYPE=text name=login value='$login' SIZE =10>");
print("<INPUT TYPE=text name=pass value='$pass' SIZe=10>");
print("<INPUT TYPE=submit>");

?>

Page 2
<?
$tmp=$login;
$tmp2=$pass;
session_start();
session_register("tmp","tmp2");
print("Here are some variable<BR>$PHPSESSID<BR>$login<BR>$pass");
print("<BR>");
print("<A HREF=createcookie.php>goto page 1</A>");

?>

The first time it works however if i go back to page 1 and try to resubmit the form with new values it doesn't change the session variables?? Any ideas?

Thanks

[Anon]

$one = "sam";
$two = "judy";
session_start();
session_register("one","two");
$one = "zorro";
echo $one; // still gives you "sam", since it's registered

//but this should work (i think)
session_unregister($one);
$one = "zorro";
echo $one; // shold read "zorro"
//and, if you want to keep the new value around . . .
session_register($one);