Integrating your website layout with HostBill is easy, you can find plenty resources here:

• Documentation of smarty – temple engine used by HostBill: http://www.smarty.net/docsv2/en/language.builtin.functions.tpl
• Useful tips and tricks when integrating templates: http://wiki.hostbillapp.com/index.php?title=Integrating_templates_-_tips_and_tricks
• Introduction to integrating templates: http://wiki.hostbillapp.com/index.php?title=Integrating_HostBill_with_your_current_website_layout