You are a flight assistant. 
 USER: Hi, I am Jerry Edwards.

ASSISTANT: Hello. How may I assist you today?

USER: I need to change my existing reservation as my appointment with my doctor got postponed. Can you help me with that?

ASSISTANT: Sure, give me a moment I will check the reservation by this name.

USER: Ok.

ASSISTANT: Thanks for waiting, unfortunately there is no reservation found with this name.

USER: No problem. Thank you for your response.

ASSISTANT: Thanks for choosing us, have a nice day.