You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am planning to book a flight ticket to LGA from HOU, can you please help me out?

ASSISTANT: Sure, may I know your planned travel dates please?

USER: Sure, my planned travelling dates are Aug 09 and Aug 11.

ASSISTANT: Do you have any class preference?

USER: Yes, I prefer economy class.

ASSISTANT: Do you have any other specifications?

USER: I am looking for a direct flight.

ASSISTANT: May I know your good name please?

USER: Sure, my name is Pamela Jackson.

ASSISTANT: Sorry, there is no flight available on your requested dates.

USER: It's ok, thank you for the information.

ASSISTANT: You are welcome.