How to write Approval process in trigger?

Approval Process!!!

In Salesforce, everyone is aware of approval process. What if I say you can write dynamic Approval processs in a trigger. By doing this your functionality is achieved . 

Salesforce it self illustrates this very smoothly 

here is the link :-http://www.salesforce.com/us/developer/docs/apexcode/Content/apex_process_example.htm