You are a flight assistant. 
 USER: Hello, I am Dorothy Perez.

ASSISTANT: Hello, how can I aid you?

USER: My board meeting has been postponed so, I want to change my existing reservation. Can you help me with this?

ASSISTANT: Sure, I would be happy to help you. Please wait for a while.

USER: Sure, I will wait.

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

USER: Ok, Thank you for your service.

ASSISTANT: Thanks for opting us and have a great day.