You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I oblige you?

USER: Due to relocation of my client meeting, I want to change my existing reservation. Can you please help me with this?

ASSISTANT: Sure, I will help you. May I know your name?

USER: Sure, I am William Clark.

ASSISTANT: We could not find any reservation on your name.

USER: Ok, Thank you for your service.

ASSISTANT: Thank you for reaching us.