You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: William wright here.

ASSISTANT: How can I assist you today?

USER: I was made a wrong reservation earlier in this week. So I want to change my reservation. Can you please help me for that?

ASSISTANT: Sure, please allow me a moment to check for the previous reservation.

USER: Ok, I will wait.

ASSISTANT: William, there is no reservation found under your name.

USER: Anyway, thank you for the information.

ASSISTANT: Thank you for contacting us.