GetITemPicture from Microsoft Dynamics Nav Webservices

Hi All,

I need to getPicture from  Navision WebServices using Codeunit. I have followed the steps given in this link( my getItemPicture Codeunit method consists of   two parameters as  String itemNo and  Holder  Picture.  What does the Holder denotes? How to pass these two parameters?

Thank You very much in Advance,