You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Ronald Evans.

ASSISTANT: How can I help you today?

USER: I would like to change my existing reservation, due to heavy rain fall. Can you please help me?

ASSISTANT: Sure, I am here to help you. wait a second.

USER: Thank you. Sure, I will wait for your response.

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

USER: No problem, thank you for checking.

ASSISTANT: Thank you for choosing us.