printing an invoice using CI

[eluser]rangana[/eluser]
Hi guys,

I'm just started CI and,I'm developing a system for a hospital as my university project, i need to print a invoice kind of thing (actually it is a small chit given to the patient, it has patient reference number, doctor unit etc.) i want to print the point at the point where patient is registered as a patient in the hospital. can you please help me to do this? any tutorial link, or simple explanation containing how to do it is good!

regards,
Rangana