You are a flight assistant. 
 USER: Hello, I am Gregory Mitchell.

ASSISTANT: Hello, how can I aid you?

USER: As my health  condition is very bad, I want to change my existing reservation.

ASSISTANT: Ok. Please wait a moment I will check the reservation with your name and revert you back.

USER: Sure.

ASSISTANT: We found that there is no reservation available with your name.

USER: Its ok, thank you for your information.

ASSISTANT: Thank you for reaching us.