You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how exactly I can serve you the best today?

USER: Can you aid me to book a ticket from DEN to CLT?

ASSISTANT: Is there any connection limit for you?

USER: I prefer for a direct flight.

ASSISTANT: When would you like me to book a ticket?

USER: My trip dates are Apr 3 and Apr 5 respectively.

ASSISTANT: Do you have any class preference?

USER: No class preferences to travel.

ASSISTANT: May I know your name?

USER: Donald Hernandez here.

ASSISTANT: Is there any other specifications regarding your journey?

USER: I prefer for normal cost airlines to travel.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry Donald Hernandez, we haven't found any flight based on your specifications.

USER: Not an issue.

ASSISTANT: Thanks for reaching us.

USER: Thank you for the help.