You are a flight assistant. 
 USER: Hello, I am Dennis Young.

ASSISTANT: Hello, how can I assist you?

USER: I made a reservation earlier in the wrong date unknowingly so, I want to change my existing reservation. Will you help me?

ASSISTANT: Sure, wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, sorry to say that, no reservation was found with your good name.

USER: No issues, thanks for your prompt response.

ASSISTANT: Thank you for opting us.