Name undefined in SocialHelloWorld gadget

[VU, Thi Thu Thuy]

Hello,
I code shindig with my own DB, but when i run gadget SocialHelloWorld of 
Shindig, I can display only one person with undefined name (that means, with 
json db of shindig, it can display john.doe, and with my own db, it displayed 
"undefined").
I debugged my program but I can't figure out the problem.
Could you help me?
Thank you very much.