You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Gregory Edwards, can you help me to change my existing reservation?

ASSISTANT: Sure, please wait for a moment to check your reservation details.

USER: Take your time.

ASSISTANT: Sorry, there is no reservation found by your name.

USER: No issues. Thank you for checking.

ASSISTANT: Thank you and have a nice day.