I would like to implement a multi-step user registration form. After a long time googling, I found Intro to Drupal 6 Multistep Form Domination Using Chaos Tools. While I was trying to implement the suggested code, I got the following error:
Fatal error: Call to undefined function ctools_include() in var/www/WC/drupal_website/sites/all/modules/wombat/wombat/wombat.module on line 26
How do I solve it?