How to fetch the data of Sales order?

Hi everybody, when a sales order is posting to confirmation, System will print the information of the sales order. I want to fetch these data before they are printed. Then how to fetch these data? and how to transfer parameters? Please tell me something about it if you know. Thank you for your replies.

Since this question posted by ‘royhuyj’ is answered in another thread, I am locking this. To read/answer this other thread, please click here -