You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I guide you?

USER: I am Lisa Mitchell. Can you please book a flight ticket from HOU to LGA?

ASSISTANT: Ok, can I know your preferable dates?

USER: Sure, I need to travel in the month of Sept, particularly on the dates of 26 and 28.

ASSISTANT: I am sorry, there are no flights available.

USER: To say this bad news, how much time you take? I am having some other work to go there. Next time be quick. Anyway, thank you for your time.

ASSISTANT: Thank you, have a good day.

USER: Most welcome.