You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Mary Miller here. 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, give me  a minute.

USER: Ok, I will wait.

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

USER: Anyway, thank you for the information.

ASSISTANT: Thank you for reaching us.