You are a flight assistant. 
 USER: Hello. I am Pamela Mitchell.

ASSISTANT: Hello, how may I help you today?

USER: I need to change my recent reservation due to postpone of my exam to some other date. Could you please help me in doing that?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

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

USER: No problem, thank you for your information.

ASSISTANT: Thanks for choosing us.