You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Can you help me to book a flight from DCA to IAH?

ASSISTANT: Sure, I will help you. Please tell us your name.

USER: Donald Campbell.

ASSISTANT: Thank you. Please tell us your travel dates.

USER: My travel dates are Oct 24 and 26.

ASSISTANT: Ok, do you have any specifications?

USER: I need to return in the afternoon time.

ASSISTANT: There is a flight with single connection in Spirit airlines and the ticket costs you 200 only in economy class. Flight departs at 1:00 hours and arrives at 11:00 hours. Can I book the ticket for you?

USER: Please do not proceed.

ASSISTANT: Sorry, there are no flights available as per your requirements.

USER: Thanks for the help.

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