You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you please help me with changing my previous booking?

ASSISTANT: Sure, may I know your name please?

USER: My name is Lisa Roberts.

ASSISTANT: Ok, please wait for a moment.

USER: Ok, take your time.

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

USER: Oh! That's fine. Thank you for checking.

ASSISTANT: Thank you for opting us.

USER: Most welcome.