You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. May I know your name?

USER: I am Benjamin Davis.

ASSISTANT: Do you want me to help you with anything?

USER: I want to attend my friend's marriage for that I reserved the ticket, but right now I am going by with other friends. So that I want change my reservation, can you help me to change my ticket?

ASSISTANT: Sure, give me a minute.

USER: Sure.

ASSISTANT: I am sorry to say that there is no reservation found.

USER: It's ok.

ASSISTANT: Thank you for providing me with your details.

USER: Thanks for your helping.

ASSISTANT: Welcome.