You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I help you today?

USER: I am Gregory Thompson. I want to change my recent reservation as my joining date got postponed. Can you help me in changing?

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry to say that, no reservation was found with your good name.

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for reaching us.