You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello,.

USER: I am Pamela Campbell.

ASSISTANT: How shall I help you?

USER: I need to cancel my existing reservation. Can you help me?

ASSISTANT: OK,give me a minute,I will let you know.

USER: Ok.

ASSISTANT: Your reservation has been cancelled. Thank you for choosing our service.

USER: Thank you for your service.