Undefined Index Problems

[ShoeLace1291]

So, for the past couple of years or so I've been using CodeIgniter to develop my PHP applications... which may have been a mistake.  As of late, I've been trying to get away from frameworks and am developing an application purely on my own.  I never had this problem with CI, but whenever I try to determine if a variable/index has been defined, I get an error.  For example, if I use an if statement to see if a session index called "mid" was defined, I get a PHP error saying that it's undefined.  Is there any way to get around this?

 

<?php
if($_SESSION['mid']){
     echo $inbox;
} else {
     echo 'Your not logged in!';
}
?>

[Psycho]

When you try to reference a variable that does not exist you may get a warning message depending upon the error level set on the server. The correct way to check if a variable has been set or not is . . . wait for it . . . isset()!

 

if(isset($_SESSION['mid'])){
     echo $inbox;
} else {
     echo 'Your not logged in!';
}

 

However, if you were really wanting to check if the value of $_SESSION['mid'] is TRUE (when it is set), then you might need to do this:

if(isset($_SESSION['mid']) && $_SESSION['mid']){