You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

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, may I know your name?

USER: My previous reservation has done with the name Amanda Lewis.

ASSISTANT: Please give me a moment to check your reservation status.

USER: Sure, take your own time.

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

USER: Ok, not an issue. May be something went wrong while booking the ticket. Thank you for providing information.

ASSISTANT: Thank you for reaching us.