You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Sandra Young here.

ASSISTANT: How can I assist 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: Ok, please wait. Sorry, no reservation found on your name to change.

USER: Anyway, thank you for the information.

ASSISTANT: Thank you for reaching us.