You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

USER: I am Kathleen Allen.

ASSISTANT: Nice to meet to Kathleen.

USER: I want to change my reservation for my sudden change of my plan, can you help me in that?

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry Kathleen, there is no reservation is found as per your travelling details.

USER: That's ok. Thank you.

ASSISTANT: Thank you for your information.