I briefly worked with Drupal several years ago, and now have come back to it for a single project. For all intents, I’m a total beginner. I need to create a new user from a custom form (html in a block.) I’ve found some info on how to do the back-end processing (this and this), but can’t figure out how to capture the form submission values in my custom module. Can I just use $_POST values? Is that allowed? Or is there some other way I’m supposed to go about it?

My initial module code looks like this:

function create_vector_user_block_info() {     $blocks['create_vector_user'] = array(     // The name that will appear in the block list.     'info' => t('Create Vector User'),     // Default setting.     'cache' => DRUPAL_CACHE_PER_ROLE,   );   return $blocks; }    function create_vector_user_submit() {     //This will generate a random password, you could set your own here   $password = user_password(8);    //set up the user fields   $fields = array(     'name' => 'user_name',     'mail' => 'user_name@example.com',     'pass' => $password,     'status' => 1,     'init' => 'email address',     'roles' => array(       DRUPAL_AUTHENTICATED_RID => 'authenticated user',     ),   );    //the first parameter is left blank so a new user is created   $account = user_save('', $fields);    // If you want to send the welcome email, use the following code    // Manually set the password so it appears in the e-mail.   $account->password = $fields['pass'];    // Send the e-mail through the user module.   drupal_mail('user', 'register_no_approval_required', $email, NULL, array('account' => $account), variable_get('site_mail', 'noreply@example..com')); } 

What I need to do is get the value of a username and email field in my custom block and pass them to the elements in the $fields array.