You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I be at your service?

USER: Can you please book a ticket in normal-cost airline?

ASSISTANT: Sure, may I know your source and destination airport codes?

USER: My source is Denver, DEN and destination is Las Vegas, LAS.

ASSISTANT: Thank you, when are you planning your trip?

USER: My travelling dates are Aug 20 and Aug 22.

ASSISTANT: May I know if you are looking for any specific depart and return time?

USER: Yes, my return time is morning.

ASSISTANT: Do you prefer either economy or business class?

USER: I prefer economy class.

ASSISTANT: Do you have any other requirement for your journey?

USER: Yes, I want single connected flight.

ASSISTANT: Sure, may I know your name please?

USER: Sure, I am Jacob Jackson.

ASSISTANT: Thank you for providing all the required details, please wait for a while.

USER: Ok.

ASSISTANT: I regret to inform you that we don't have any flight available which meets all your journey needs.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you.