You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I would like to book a ticket to DC - DCA from TX - IAH and I wish the ticket to be booked by the name as Barbara White. The travel dates are 11/21 to 11/23.

ASSISTANT: Thanks for giving all the information. Please hang on a moment.

USER: Sure.

ASSISTANT: We are very sorry to notify you that there is no flight available according to your criterion. Thanks for reaching us.

USER: Thank you for your response.