You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you?

USER: I need to travel CLT and IAH, can you please reserve flight ticket?

ASSISTANT: Sure, I will help you. Please send your travelling dates.

USER: My travelling dates are July,17 and July,19.

ASSISTANT: Do you have any preferences?

USER: I need single connecting flight.

ASSISTANT: May I know your name?

USER: Myself Dorothy Smith.

ASSISTANT: Sorry, there is no flight available with your requirements.

USER: Oh! Sad to hear that. Anyway, I will find another alternative to complete my journey.

ASSISTANT: You are welcome, have a nice day.