How to add new Fields to default section of Purchase Header

A-O-A,all

i m working with ax 2012 ssrs, i want to customize the purchase order report header section, i open a exist purchase order open it in VS12 for customization ,i go to design mode, and add new fields in header section of the report,also make some change to existing fields of header ,but when i preview the report ,nothing happend,

so my question is that i want to add new information regarding to company section in header also about vendor in purchase order header section..

so how it will be achived..

Regards,,and Thanks in advance...