You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I know your good name?

USER: My name is Lisa Clark.

ASSISTANT: How can I assist you?

USER: Owing to emergency I had request for this change reservation, can you please help me to change an existing reservation?

ASSISTANT: Sure, I will help you. Give me a minute, I will be back and revert you.

USER: Sure, I will wait.

ASSISTANT: Thank you for your patience. There is no reservation found with your name.

USER: That's not a problem.

ASSISTANT: Thank you for choosing us, have a great day.

USER: Thanks for your information.