unfollow.php

<?php 
session_start();
$user_id = $_SESSION['user_id'];
?>
<?php
if($_GET['userid']  && $_GET['username']){
	if($_GET['userid']!=$user_id){
		$unfollow_userid = $_GET['userid'];
		$unfollow_username = $_GET['username'];
		include 'connect.php';
		$query = mysql_query("SELECT id
							   FROM following 
							   WHERE user1_id='$user_id' AND user2_id='$unfollow_userid'
							  ");
		mysql_close($conn);
		if(mysql_num_rows($query)>=1){
			include 'connect.php';
			mysql_query("DELETE FROM following 
				WHERE user1_id='$user_id' AND user2_id='$unfollow_userid'
				");
			mysql_query("UPDATE users
				SET following = following - 1
				WHERE id='$user_id'
				");
			mysql_query("UPDATE users
				SET followers = followers - 1
				WHERE id='$unfollow_userid'
				");
			mysql_close($conn);
		}
		header("Location: ./".$unfollow_username);
	}
}
?>