You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I would like to change my existing reservation, as my planned trip with my friends got postponed. Can you please help me out?

ASSISTANT: Sure, I can help you with that. May I know your good name please?

USER: Thank you for considering my request. My name is David Thomas.

ASSISTANT: Ok, please wait for a while.

USER: Sure, I will wait for your response.

ASSISTANT: David Thomas, there is no active reservation found under your name to do changes in that.

USER: Ok, not a problem. Thank you for the information.

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

USER: Thank you for your service.