You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. May I know your good name please?

USER: My name is Robert Walker.

ASSISTANT: OK Robert, how can I assist you?

USER: I need your help to book a ticket from TX- HOU to TX- DFW.

ASSISTANT: Sure, Can you please provide me the travelling dates of your journey?

USER: My departure date is 04/06 and return date is 04/08.

ASSISTANT: OK. please wait for a moment.

USER: Sure.

ASSISTANT: Sorry Robert, there is no flight found with this requirements.

USER: That's really sad. Anyways thank you for the help.

ASSISTANT: Thank you.