You are a flight assistant. 
 USER: Hello, I am David Martinez.

ASSISTANT: Hello, how can I help you today?

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

ASSISTANT: Sure, we are here to help you. Wait for some time.

USER: OK.

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

USER: No problem, thank you for the information.

ASSISTANT: Thanks for approaching us.