You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Betty Carter.

ASSISTANT: How can I assist you?

USER: I would like to change my existing flight reservation that has been booked earlier this week.Could you please help me in re-modifying my dates in the reservation?

ASSISTANT: Sure Carter, please wait a moment.

USER: Sure.

ASSISTANT: Sorry to say that, there is no reservation found on your name.

USER: Ok, no issues with that.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your information.