You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: I am Carolyn Garcia. Due to sudden rainfall at my source I want to change my existing reservation. Can you please help me with this?

ASSISTANT: Sure, I will help you in changing the ticket.

USER: Thank you.

ASSISTANT: Sorry, there are no reservations found.

USER: Ok, no problem. Thank you for checking.

ASSISTANT: Thank you for reaching us.