You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I provide assistance for you?

USER: I have to change my father's reservation because he is not well, can you please help me?

ASSISTANT: Sure, I am glad to help you. Could you please let me know his name to check the reservation details?

USER: Sure, his name is Gregory Lee.

ASSISTANT: Ok, please wait a moment I will check and proceed further.

USER: Take your time.

ASSISTANT: Sorry to say, I did not find any reservation on the name of Gregory Lee.

USER: Not an issue, thank you for checking.

ASSISTANT: You are welcome. Have a nice day.