Insert notes in a datagrid

[JFB]

Hi All,
I have a datagrid on asp.net using VS2003.
In this Datagrid I have my contacts recods, how can I insert a note field?
Can I put a image button so when it's click a window will popup... or maybe
a second empty row for each contact wil open...
any ideas?? how can perform this...
Tks

JFB