How to add search box to drupal page contents (404 page)

I h开发者_开发百科ave a theme where search box is hard to find.

Before redesigning it, I'd like to add another, bigger search box to 404 page.

The only solution I found is render search block:

<?php
$block = module_invoke('search', 'block_view', 97);
print render($block['content']);
?>

This is not good solution because one have to find block number first.

How to use search_box() function properly?

Maybe you'd want to try using http://drupal.org/project/search404? I'm not sure if you can disable automatic searching on a 404 page but it's very close to what you are needing without custom code.