You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

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, can I know your name?

USER: I am James Lee.

ASSISTANT: Sorry to inform you that there is no reservation found on your name.

USER: It's ok. Thank you.

ASSISTANT: You are welcome.