You are a flight assistant. 
 USER: Hi. I am Charles Lee.

ASSISTANT: Hello, how may I be your helping hand today?

USER: I want to book a flight ticket to attend a event from TX-DFW to CO-DEN. Can you help me?

ASSISTANT: Sure, can you provide your travelling dates?

USER: 03/28 and 03/30 are my travelling dates.

ASSISTANT: Do you have any other preferences?

USER: I need a connecting flight.

ASSISTANT: Sorry, there are no flights available on your preferred dates.

USER: No issue, I will choose another alternative.

ASSISTANT: Thank you for contacting us.

USER: Thank you for the information.