PHP, cookies, signing in

[Dustyshouri]

So I was trying to work on a very simple sign in script for my site, so they can either sign in as a teacher or student, and it checks the appropriate password, and sets a cookie. Having some problem though. I keep getting this message whenever I try to set the cookie(Line 255 is the line the setcookie is on):

Warning: Cannot modify header information - headers already sent by (output started at urlstuffhere/index.php:6) in urlstuffhere/index.php on line 255

PHP Code:

      <?php
        $user = $_POST["user"]    ;
        $password = $_POST["password"]    ;
        $year = 60 * 60 * 24 * 365 + time(); 

        switch ($user) {
          case teacher:
            if ($password=="********") {
              setcookie(user,Teacher,$year);
            }
            break;
          case student:
            if ($password=="********") {
              setcookie(user,Student,$year);
            }
            break;
          default:
        }

        if (isset($_COOKIE["user"]    )) {
          echo "You are signed in as a " . $_COOKIE["user"]     . ", click here to sign out.";
        } else {
          echo "<form action='index.php' method='post'>";
          echo "<select name='user'>";
          echo "<option></option>";
          echo "<option value='teacher'>Teacher</option>";
          echo "<option value='student'>Student</option>";
          echo "</select>";
          echo "<input type='password' name='password' />";
          echo "<input type='submit' value='Sign in' />";
          echo "</form>";
        }

      ?>

[Dustyshouri]

Okay, scratch that bit. I fixed that problem, didn't know the cookie script had to be set before the html tag... anyways, still having problems. It's just not setting the cookie at all. It won't give an error, I've even taken scripts directly from tutorial sites and tried them and they aren't working. I don't have cookies blocked either.

[gamerman0203]

I'm not much of a PHP buy, more ASP than anything, but I'm going to take a shot in the dark:

where you're setting your cookie, you don't have the "$" before "user". It seems to me that when calling a variable, you need to call it how it is set. But I don't know anything about php so forgive me if I'm wrong.

[DJ-Zep]

Please post the source code for index.php so that I can find out exactly what is going wrong.