You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: Due to sudden change in the climatic conditions, I would like to change my program to other days.

ASSISTANT: Sure, we are here to help you.

USER: So, can you help me in change in existing reservation?

ASSISTANT: Can I have your name to proceed?

USER: I am Catherine Anderson.

ASSISTANT: Ok, please hold a moment.

USER: Sure.

ASSISTANT: Thank you for your time, sorry, no reservation found with your name.

USER: Ok. Thank you.

ASSISTANT: Thank you for availing us.