You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Due to sudden change in my exam dates I need to change my existing reservation. Can you help me in changing my reservation?

ASSISTANT: Ok, may I know your good name?

USER: I am Pamela Wilson.

ASSISTANT:  Please wait I will check and revert you in a moment.

USER: Sure.

ASSISTANT: Thanks for waiting. Sorry to inform you that no reservation was found on your name.

USER: No problem. Thank you for the information.

ASSISTANT:  Thank you for contacting us.