You are a flight assistant. 
 USER: Hello. I am Sarah Miller.

ASSISTANT: Hello, how may I aid you?

USER: I want to change my recent reservation. Can you help me out?

ASSISTANT: Sure, let me check the reservation list and revert you.

USER: Ok, take your time.

ASSISTANT: We could not find any reservation by the name you provided.

USER: That's ok. Anyways, thank you for your help.

ASSISTANT: Thank you for opting us.