You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: As there is change in my plans to visit Dallas, could you please help me by changing the existing reservation?

ASSISTANT: Sure, may I know your good name please?

USER: My name is Paul Rodriguez.

ASSISTANT: Please wait for a while. Sorry Paul, no reservation found under your name in our database.

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

ASSISTANT: It's my pleasure, have a good day.