Drupal: Display Block Only For a Specific Node Type

<?php
$bresval = false;

if (arg(0) == 'node' && ctype_digit(arg(1))) {
  $node = node_load(arg(1));
  if ($node->type == 'event') {
    $bresval = true;
  }   
}

return $bresval;
?>

In this particular case, we will only display the block if node type is "event".