You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Can you help me to change my recent reservation?

ASSISTANT: Sure, may I know your name please?

USER: Joseph Lee here.

ASSISTANT: Ok, please wait for a while.

USER: Sure, take your time.

ASSISTANT: Sorry, there was no reservation found with your given name.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for opting us.