You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I am Melissa Walker. I would like to see my grandfather as he is unwell, can you please help me to book my flight ticket from LAS to HOU?

ASSISTANT: Sure, we are here to help you in booking. May I know on which dates you are willing to travel?

USER: I want to depart on Jan 12th and I will return back on Jan 14th.

ASSISTANT: Do you have any other specifications?

USER: Yes, I prefer for an economy class.

ASSISTANT: Please let me know if you need a connecting flight.

USER: Flight should have single connection.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Thank you for waiting, I regret to inform you that there are no flights obtained on your journey dates to book a flight ticket.

USER: Sad to hear that. Anyway, thank you for checking.

ASSISTANT: Thank you for approaching us.