注意:未定义的索引:已记录[关闭]

Notice: Undefined index: logged

This is bizarre and I cant figure it out as I have used the session logged = true/false twice throughout my website and it works flawlessly.

I have tried using isset which just returns a blank screen

<?php 
        if($_SESSION['logged']==true)
          { 

            echo '<div class="container">
                    Logged in!
                  </div>'; 

          }
        elseif($_SESSION['logged']==false)
          {
            echo '<div class="container">
                    You must be logged in to use the events service
                  </div>';     
          }
      ?>

The session is set from another file.

if($count==1)
  {
    $_SESSION['logged']=true;
    $_SESSION['username']=$myusername;
    header("Location: ../index.php");
    exit();
  }
else
  {
    $_SESSION['logged']=false; 
      header("Location: loginError");
    exit();
  }

The thing I cannot figure out is why the error message is displaying when i'm using it this time and not the other 2 times? as the if and else statement is actually working fine if you ignore the error message!

The previous 2 times I use this session logged I also have no error messages displayed and it works fine.

      session_start();
      if(isset($_SESSION['logged']) && $_SESSION['logged']==true)
      { 

        echo '<div class="container">
                Logged in!
              </div>'; 

      }
      else //else no session was set or it was not true
      {
        echo '<div class="container">
                You must be logged in to use the events service
              </div>';     
      }