You are a flight assistant. 
 USER: Hi,. I am Gregory Hill.

ASSISTANT: Hello, how may I be there for you?

USER: I want to change my existing reservation due meeting was postponed. Can you help me in changing my reservation?

ASSISTANT: Sure, I can help you with that.

USER: Thank you.

ASSISTANT: Please wait for a while. I will check the current status and revert you.

USER: Sure.

ASSISTANT: Thank you for being patient.

USER: Ok.

ASSISTANT: We could not find any reservation on the name you provided above.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for reaching us.