You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Shirley Clark here.

ASSISTANT: Clark, how can I guide you?

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

ASSISTANT: Sure, I will help you. Please wait for a while.

USER: Ok, I will wait.

ASSISTANT: Sorry, no reservation found on your name.

USER: Anyway, thank you for the information.

ASSISTANT: It's my pleasure.