Good day!

I am having a little problem regarding clearing sessions.

I have a link named LOGOUT in php.. when this link is click, I want to clear and detroy all sessions and redirect the user to index.php page.

thank you for helping!

There's a function that clears session variables for you: session_destroy().

Also, the function header() will let you redirect to any page. E.g.

header("Location: index.php");

how to put in in click event of the link?

You don't want to put it as an onclick event, as that's a bit more complicated and assumes that the user has JavaScript. I'd suggest making a file that destroys the session and redirects the user. This is all you need (I'm not even sure you need to add session_start(), but it doesn't hurt):

header("Location: index.php");

Tnx for helps!