You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Please book a flight ticket from DEN to PHX.

ASSISTANT: Sure, can you please share your travelling dates?

USER: July, 2 and July, 4 are my travelling dates.

ASSISTANT: Ok, may I know your name please?

USER: Justin Young here.

ASSISTANT: Ok, please share your connection limit.

USER: I need single connection.

ASSISTANT: Do you have any other specifications?

USER: I need to return at evening time in normal cost airline service only.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Thank you for your time, sorry no flights found with your details.

USER: That's ok, thank you for the information.

ASSISTANT: Thank you for reaching us, have a nice day.