You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I serve you today?

USER:     I want to book a flight ticket from IAH To LAX, can you help me with booking please?

ASSISTANT: Sure, it is my pleasure to help you with the booking.

USER: Thank you.

ASSISTANT: May I know when are you willing to travel?

USER: I am willing to travel on dates 05/10 and 05/12.

ASSISTANT: Do you have any restriction with your depart and return time?

USER: I want to return at afternoon.

ASSISTANT: Which airline do you prefer to travel?

USER: I need to travel in normal cost airline.

ASSISTANT: Do you have any other preference?

USER: I need a connecting flight.

ASSISTANT: May I know your name please?

USER: I am Richard Lee.

ASSISTANT: Sorry, we can not provide you any flight as not a single one is meeting all your restriction.

USER:      That's ok, thank you for the response.

ASSISTANT: Thank you for reaching us.