Dan,
What i've done before now is created an "Error Dictionary" file which contains the following:
<?php
$e1 = "Sorry, your password was invalid. Please try again";
$e2 = "There was a problem processing your request";
// etc etc.
?>
Then, in the top of all your pages you could include this file.
In your header() function you could do something like this:
header("Location: shows.php?e=2");
Then, insert a bit of script into your shows.php file to process the error code.
if($_GET['e']){
$num = "e".$_GET['err']; // Creates e2
$ref = ${$num}; // Creates $ref to equal "$e2";
echo $ref; // Echo's the error reference from the dictionary file
}
There is probably a cleaner and quicker way to do this, but its just an idea for you.
Let me know if this helps any.
Dave