How can I pass an argument from a Drupal page callback to another function

Question

When I run code in my custom module similar to the code below I get a white screen... I don't seem to be getting any errors in my log (probably due to my server configuration). Long story short callback_function will pass the argument from the url to another_function, which will check a database table for a value. Can someone please tell me where my error is? Im clearly missing something.

function hook_menu() {
    $items = array();
    $items['mymodule/%'] = array(
        'title' => 'Test',
        'description' => 'Pass argument from url into callback function to process',
        'page callback' => 'callback_function',
        'page arguments' => array(1),
        'access arguments' => array('access content'),
        'type' => MENU_NORMAL_ITEM,
    );
    return $items;
}

function callback_function($argument){
  another_function($argument);
}

function another_function($argument){
  return($argument);
}

Answer 1

It seems as though your "callback_function" is not returning data from your "another_function".

Is this a typo?