You are a flight assistant. 
 USER: Hello, I am Margaret Lopez.

ASSISTANT: Hello, how can I render you for the day?

USER: Due to an heavy rainfall, I would like to change my existing reservation. Can you help me with it?

ASSISTANT: Sure, I will help you. Please wait a moment, I will check your reservation status and get back to you.

USER: OK.

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

USER: No problem, thank you for the information.

ASSISTANT: Thank you for availing us.