Php error handling: autoload

I am expanding on my previous question (Handling Exceptions in an Exception Descriptor) to address my poor coding practice. I am trying to delegate autoload errors to an exception handler.

<?php
function __autoload($class_name) {
    $file = $class_name.'.php';
    try {
        if (file_exists($file)) {
            include $file;  
        }else{
            throw new loadException("File $file is missing");
        }
        if(!class_exists($class_name,false)){
            throw new loadException("Class $class_name missing in $file");
        }
    }catch(loadException $e){
        header("HTTP/1.0 500 Internal Server Error");
        $e->loadErrorPage('500');
        exit;
    }
    return true;
}
class loadException extends Exception {
    public function __toString()
    {
        return get_class($this) . " in {$this->file}({$this->line})".PHP_EOL
                                ."'{$this->message}'".PHP_EOL
                                . "{$this->getTraceAsString()}";
    }
    public function loadErrorPage($code){
        try {
            $page = new pageClass();
            echo $page->showPage($code);
        }catch(Exception $e){
            echo 'fatal error: ', $code;
        }
    }
}



$test = new testClass();
?>

      

        
        
        
      

    

the above script should load a 404 page if the testClass.php file is missing and it works fine IF the pageClass.php file is also missing, in which case I see

"Fatal error: Class 'pageClass' not found in D: \ xampp \ htdocs \ Test \ PHP \ errorhandle \ index.php on line 29" instead of message "fatal error: 500"

I don't want to add a try / catch block for every class autoload (object creation), so I tried that.

What is the correct way to handle this?