You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. May I know what kind of assistance your are looking for?

USER: Due to change in my plans to visit Dallas, I would like to change my existing reservation. Can you help me with this?

ASSISTANT: Sure, I am glad to help you. Please give me a moment to check your ticket status.

USER: Sure.

ASSISTANT: May I know your name?

USER: My name is Margaret Edwards.

ASSISTANT: Sorry Edwards, no reservation is found by your name.

USER: Ok, not an issue. Thank you for providing information.

ASSISTANT: Thank you for reaching us.