Landing page, how to deal with it

Landing page
Include ' coon.php ';
@ $username =$_post[username];
@ $password =$_post[password];
$MD 5_pass=md5 ($password);
if (@$_get[out]) {
Setcookie ("Cookie", "out");
echo "";
}
$query = "Select Username,password from user where username= ' $username '
and password= ' $md 5_pass ' ";
$result =mysql_query ($query);
$num _rows=mysql_num_rows ($result);
$row =mysql_fetch_array ($result);
if ($num _rows>0)
{
$passsword 1= $row [' Password '];
if ($passsword 1== $password)
{
Setcookie ("Cookie", "OK");
echo "";
}
}
else {
echo "";
}
if (@$_cookie[' COOKIE ']!= ' OK ') {
?>


}else{
?>
Exit
}
?>
You can't just log in, you can't quit.

------Solution--------------------
_cookie on the second page (re-refresh) to take effect, you directly in a page to create and judge of course it is not possible to change into a session
------Solution--------------------
That $query you write like that seems a little dangerous.
------Solution--------------------
Http://blog.sina.com.cn/s/blog_71ed1b870100yxz8.html
PHP Simple Login Exit code
------Solution--------------------
discuss
......

......
Exit

