You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Richard Clark.

ASSISTANT: How could I render you today?

USER: I want to change my reservation, can you please help me with it?

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: There is no reservation found with your given name.

USER: No problem, thank you.

ASSISTANT: Thank you for choosing us.