You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I support you?

USER: Can you please help me with booking a flight from DFW to DEN for my business trip?

ASSISTANT: Ok, May I know your travelling dates?

USER: My journey dates are from Feb 20 to Feb 22.

ASSISTANT: Ok, May I know your good name?

USER: My name is Patrick Collins.

ASSISTANT: Ok, Do you have any class preference?

USER: No.

ASSISTANT: Ok, Do you prefer direct flight or connected flight?

USER: I need single connecting flight.

ASSISTANT: Ok, Do you have any other preferences?

USER: No, thanks for asking.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Thank you for your time, we did not find any flights with your given requirements.

USER: Oh! That's fine. Thank you for checking.

ASSISTANT: Thank you for choosing us.

USER: Welcome.