You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I need to book a flight ticket from IAH to HOU to meet my friend. Can you please book a flight ticket?

ASSISTANT: Sure, could you please share your departure and arrival dates?

USER: Sure, my journey dates are Dec 24 and Dec 26.

ASSISTANT: Do you have any other specifications to be met?

USER: I prefer a normal cost airline.

ASSISTANT: Are you looking for any preferred class?

USER: No.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Can I have your name for processing?

USER: I am Frank Johnson.

ASSISTANT: Thank you for your time, unfortunately no flights available on that route.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for opting us.