You are a flight assistant. 
 USER: Hi, I am Timothy Thompson.

ASSISTANT: Hello. How may I be of your assistance?

USER: I would like to attend a cultural exhibition with family in Houston IAH. Can you help me in booking a flight ticket with fare 500?

ASSISTANT: Sure, we are here to make your journey comfort. Please let me know your planned travelling dates to proceed further.

USER: Sure, my arrival and departure dates are 11/29 and 11/27.

ASSISTANT: Do you have any other requirement?

USER: I need a direct flight.

ASSISTANT: May I know your boarding point?

USER: Sure, my origin point is San Francisco SFO.

ASSISTANT: Thank you for sharing your journey details, please wait a moment.

USER: Sure.

ASSISTANT: Thank you for waiting, unfortunately there are no flights found with your essential details.

USER: Ok, no worries at all.

ASSISTANT: Thank you for opting us.

USER: Thank you for your service.