You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I guide you today?

USER: Frank Allen here.

ASSISTANT: Hello Frank.

USER: I want to visit Space center in Houston.Can you please help me for booking the ticket?

ASSISTANT: Sure, may I know your nearest airport codes for booking?

USER: My airport codes are form IL-ORD to TX-HOU.

ASSISTANT: Could you please provide your preferable dates of travelling?

USER: My departure date is 03/17 and return date is 03/19. Make sure my connections limit is 0.

ASSISTANT: Ok, please wait a moment to the availability of flight. Sorry Frank, there are no direct found with your requested dates of travelling.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for reaching us, have a nice day.