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

ASSISTANT: Hello, how may I help you today?

USER: Due to an emergency meeting, I want to change my reservation. Can you help me with it?

ASSISTANT: Sure, I am happy to help you. Please wait for some time.

USER: OK.

ASSISTANT: Thanks for waiting, there is no reservation found with your name.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.