You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I am Alexander Rodriguez. Can you book a flight ticket from ORD to LAS?

ASSISTANT: Sure, I am here to help you. May I know your trip dates?

USER: My trip dates are from Sept 25 to Sept 27.

ASSISTANT: May I know your class preference?

USER: I am comfortable with any class.

ASSISTANT: Ok, do you have any other preferences?

USER: I want to depart in the morning time.

ASSISTANT: There is a flight available in Frontier airlines having single connection and the ticket fare is 200 only. Can I book the ticket for you?

USER: I want a flight ticket with normal cost. Can you please check once?

ASSISTANT: Ok, please wait. Let me check.

USER: Sure.

ASSISTANT: Sorry, there is no flight available as per your requirements.

USER: Ok, No issues. Thank you.

ASSISTANT: You are welcome and thank you for choosing us.