You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Mary Collins.

ASSISTANT: How can I assist you today?

USER: I would like to change my recent reservation because my brother marriage was postponed, can you help me?

ASSISTANT: Sure, I can help you with that. Please wait for a while.

USER: Sure, I will wait for your response.

ASSISTANT: Mary Collins, there is no active reservation found under your name to do modifications in that.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for choosing us, have a nice day.