You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I want to change my existing reservation due to heavy rainfall, can you help me in it?

ASSISTANT: Sure, may I know your name please?

USER: My name is Margaret Smith.

ASSISTANT: Ok, please wait for a while, I will check and get back to you.

USER: Sure.

ASSISTANT: Sorry, there was no reservation found with your name.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for opting us.