You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I help you?

USER: I am Helen Smith,Can you please book a flight ticket.

ASSISTANT: Sure, Can I know your journey dates?

USER: yes,I need a ticket from Houston to New York.

ASSISTANT: Can I know the airport codes for booking?

USER: TX-HOU to NY-LGA.

ASSISTANT: OK, Thank You. Please tell me that in which dates u need the booking?

USER: Departure on July/31 and return on Aug/02.

ASSISTANT: OK, Please wait a moment.

USER: Departure time should be afternoon.

ASSISTANT: Do you need any connection limit?

USER: yes, I need one connection with price limit 1000.

ASSISTANT: OK, Just wait. Sorry, There are no flights for your requested dates.

USER: OK,Thank you.

ASSISTANT: Thank You Helen Smith.