Notice: Undefined index: version in legal_version_check() (line 769)

I try to debug, this is my first time debuging drupal

function legal_version_check($uid, $version, $revision, $legal_account = array()) {
  if (empty($legal_account)) $legal_account = legal_get_accept($uid);

  if ($legal_account['version'] == $version && $legal_account['revision'] == $revision) {
    $accepted = TRUE;
  }
  else {
    $accepted = FALSE;
  }

  return $accepted;
}

$legal_account is empty when user not accepted any T&C yet,
so $legal_account['version'] and $legal_account['revision'] daon't have any value
this causing error.

Question:
- why error message only showed in admin? is the warning message hidden on original user?
- can isset($legal_account['version']) check used for skipping this error? i try this can worked out

so the code would become:

function legal_version_check($uid, $version, $revision, $legal_account = array()) {
  if (empty($legal_account)) $legal_account = legal_get_accept($uid);

  if (isset($legal_account['version']) && isset($legal_account['revision'])) { 
      if ($legal_account['version'] == $version && $legal_account['revision'] == $revision) {
        $accepted = TRUE;
      }
      else {
        $accepted = FALSE;
      }
	} 
	else {
	  $accepted = FALSE;
	}

  return $accepted;
}

need review