You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I render you today?

USER: I am invited to inaugurate Google in SFO, can you help me to book the flight ticket on 05/16?

ASSISTANT: Sure, we are glad to help you.

USER: Thank you.

ASSISTANT: Can you please provide your boarding point?

USER: Sure, it's DEN.

ASSISTANT: How much you can afford for airfare?

USER: I can pay up to 500. And I need a direct flight.

ASSISTANT: Kindly ensure your arrival date?

USER: My return date would be 05/18.

ASSISTANT: May I know your name please?

USER: Sure, Anna Allen is my name.

ASSISTANT: Thank you for sharing your details, we did not find any flights matching your details.

USER: No issue, I will choose another alternative.

ASSISTANT: Thank you for reaching us.