You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: I am Karen Roberts, want to alter my recent reservation because I made my booking with wrong travelling dates. Please help me out with that.

ASSISTANT: Sure, give me a minute.

USER: Ok.

ASSISTANT: Sorry Roberts, there is no reservation find on your name.

USER: It's ok, not an issue. Anyway, thank you for your help.

ASSISTANT: You are welcome.