You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Samantha Harris.

ASSISTANT: How can I aid you?

USER: I need to change my recent reservation due to change of dates of my conference meeting has been postponed. Could you please help me in doing that?

ASSISTANT: Sure, I will help you. Give me a minute.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found under your name.

USER: No problem, thank you for valuable information.

ASSISTANT: Thank you for reaching us.