Function Module For Item Level Details of a Sales Order

Hi Guys,

I have to get the item level details for a particular sales document no ..I want to know if there is any function module existing for the same.

Also I need any function module for getting the contact information such as contact form (KNVK-ANRED),contact name(KNVK-NAM1),contact name(KNVK-NAMEV),Contact number (KNVK-TELF1).