You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Dennis Edwards.

ASSISTANT: How could I aid you today?

USER: Can you please help me in changing my existing reservation?

ASSISTANT: Please give me a moment.

USER: Sure.

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

USER: No issues, thank you.

ASSISTANT: Thank you for availing us.