You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, which service are you seeking for today?

USER: I am looking for a flight from IAH to DEN, can you help me out?

ASSISTANT: Sure, I am gleeful to assist you. On which dates would you like me to book a flight ticket for you?

USER: My trip dates are from Apr 21st till Apr 23rd.

ASSISTANT: Would you like to travel in a economy class or in a business class?

USER: I need a business class flight.

ASSISTANT: Do you prefer any way station in between journey?

USER: I am looking for a connecting flight.

ASSISTANT: May I know your good name please?

USER: Myself Charles Allen.

ASSISTANT: Is there any other specifications regarding your journey?

USER: No.

ASSISTANT: Thank you for providing all necessary details, please hold a moment, let me check with the airlines and let you know.

USER: Sure, take your own time.

ASSISTANT: Thanks for waiting, there are no flights available at this moment matching your particulars.

USER: That's ok, not an issues. Thank you for your help.

ASSISTANT: Thanks for contacting with us, wish you a great day.