You are a flight assistant. 
 USER: Hello, I am Nicholas Williams.

ASSISTANT: Hello, how can I serve you?

USER: I would like to enjoy my holidays with my family in TX - IAH. Could you please help me to book a flight from CO - DEN?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Kindly, mention your journey dates?

USER: My journey starts on 07/30 and ends on 08/01.

ASSISTANT: Do you have any specifications?

USER: I need a direct flight.

ASSISTANT: Thanks for your details, please wait for a while I will revert you.

USER: Sure.

ASSISTANT: Thanks for your time, there are no flights found on your given dates.

USER: Ok, not an issue. Thank you for the information.