You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am planning to visit Dallas for vacation with my friend, who lives at there. Can you book a flight for me?

ASSISTANT: Can I know your airport codes?

USER: My source point is IAH and my destination is DFW.

ASSISTANT: Let me know your travelling dates.

USER: I plan to travel on May 16 and return on May 18.

ASSISTANT: Do you have any preference?

USER: I want my return flight in afternoon. Please book me a connecting flight to Dallas.

ASSISTANT: Connecting flight can be booked with United airlines for price 100 having flight number 1013. Shall I book a ticket?

USER: Ok, it is good for me.

ASSISTANT: Let me know your name.

USER: My name is George Brown.

ASSISTANT: Ticket is booked.

USER: Thank you for helping me.

ASSISTANT: Thank you.