Session not destroying properly

[Anon]

Got a problem with sessions.

On my index page, there's a place for people to login. Well, when I test with two different user names (mike and jlo) it reverts to the first one when login fails. For example:
I enter in user name "myuen" and a wrong password. I get my "Password/Username invalid".

The page refreshes, the username slot already has myuen in it from the last entry, I erase it, enter in a new username "jlo" and the correct password and it will not log me in.

I know once you attempt to login, it saves the username as a session variable. On my index.php page, I have a script that checks if a session exists (particularly the Username), if it exists, it destroys it other wise continue on. Any ideas on how to fix this?

Here's my coding:
<?PHP
//destroys session if it exists
if (session_is_registered("CUserName"))
{
session_destroy();
}

//register username session
session_register("CUserName");
$CUserNameSession="CUserName";

//SNIP
?>

[Anon]

Change:

<?PHP
//destroys session if it exists
if (session_is_registered("CUserName"))
{
session_destroy();
}

<?PHP
//destroys session if it exists
if (session_is_registered("CUserName"))
{
session_destroy();
header("Location: $PHP_SELF");
}

Using session_destroy() destroys the session data for any subsequent scripts, not the currently executing one, so you need to reload the page to reflect that.

[Anon]

Thanks for the suggestion. I gave it a shot but it's still doing to same thing. Any other ideas?