[PHP]Guess It Dont Work?[PHP]

[Li1M0ST3Rz]

Okay i am using if else endif statements, and it works but don't work.
Working:

& Don't Work:

Odd?
My opinion is else dont work
PHP Snippet:

<?php
        if($_SESSION['logged_in'] = TRUE):
        {
                echo $_SESSION['username'];
        }else:{
        echo '<b>Guest</b>';
        }
        endif;
        ?>

 

[Kryptos]

<?php
        if($_SESSION['logged_in'] == true && isset($_SESSION['username'])):
        {
             echo $_SESSION['username'];
        }else{
        echo '<b>Guest</b>';
        }
        ?>

 

[GarettM]

<?php
  if($_SESSION['logged_in'] == true && isset($_SESSION['username'][1])):
  {
            echo $_SESSION['username'];
  }else{
        echo '<b>Guest</b>';
  }
?>