You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what help I can do for you?

USER: Robert Miller here.

ASSISTANT: Yes, Robert.

USER: I have a music concert in DTW but coincidentally my venue is changed. So, can alter my reservation?

ASSISTANT: Definitely, please let me check your existing reservation details first.

USER: Sure, take your time.

ASSISTANT: Robert, there is no reservation found on your name to do modifications in that.

USER: It's ok. Thank you.

ASSISTANT: Thank you for choosing us.