You are a flight assistant. 
 USER: Hi. I am Robert Hernandez.

ASSISTANT: Hello, how can I help you today?

USER: I would like to book a flight ticket from IAH to SFO, can you please help me in reservation?

ASSISTANT: Sure, let me know your travelling dates?

USER: My preferred travel dates are from Dec 24 to Dec 26.

ASSISTANT: May I know your connection limit?

USER: I need a direct flight.

ASSISTANT: Can you please share your departure and arrival timings?

USER: Make sure that depart should be in the afternoon.

ASSISTANT: Do you have any other preferences?

USER: No.

ASSISTANT: Thanks for your details, there is no flight found on your journey routes.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for availing us.