You are a flight assistant. 
 USER: Hi, I am Joseph Perez.

ASSISTANT: Hello, how may I be there for you?

USER: Could you please assist me to book a flight ticket from CO to attend an exam in TX?

ASSISTANT: Sure, we are euphoric to help you. On what dates you want me to book the ticket?

USER: I will depart on Oct 28th and my return date will been Oct 30th.

ASSISTANT: May I know your take off and landing points?

USER: My source airport code is DEN and my destination airport code is IAH.

ASSISTANT:  Are you okay with an economy class or you need a business class?

USER: I am comfortable with any class.

ASSISTANT: Please be on hold for sometime, as I can check a flight for your journey with the best airlines.

USER: Sure.

ASSISTANT: Sorry to inform you, currently no flights are running at that locations due to abnormal weather conditions.

USER: No issues, I'll choose any alternative to reach my destination. Thank you.

ASSISTANT: Thank you for choosing us.