You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: Can you help me to change dates in my existing reservation?

ASSISTANT: Sure, may I know your name please?

USER: Myself Dorothy Miller.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there was no reservation found with your given name.

USER: No issue, anyway thank you for checking.

ASSISTANT: Thank you for opting us.