You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

USER: Sharon Campbell here. Can I change my travel dates on my ticketed flight. Can you help me in changing my flight ticket reservation?

ASSISTANT: Sure, We are here to help you.

USER: Ok.

ASSISTANT: Please wait  a while.

USER: Sure.

ASSISTANT:  Thank you for waiting, but I am sorry to say that, there is no active reservation found with your name in our database to change it.

USER: Not a problem. Thank you.

ASSISTANT: Thank you for opting us.