You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Laura Johnson.

ASSISTANT: Can you please tell me how can I aid you?

USER: As my meeting got postponed, I would like to change my existing reservation to Dallas. Can you please help me with this?

ASSISTANT: Ok, please wait for a while I will check and let you know your reservation status.

USER: Sure, take your own time.

ASSISTANT: Thank you for waiting. I did not find any previous reservation on your name to change.

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

ASSISTANT: It might be happen, anyway thank you for reaching us.