You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Barbara Carter, want to change my previous reservation because I made my booking with wrong travelling dates. Please help me out with that.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: There is no reservation found with your name.

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

ASSISTANT: Most welcome.