You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: Will you please book a ticket for me from DCA to LAX?

ASSISTANT: Sure, may I know your dates of travel as well as your name please?

USER: Yes, I want to make a trip from 02/20 to 02/22 and myself Pamela Lopez.

ASSISTANT: OK, please hold on. Sorry Pamela, there is no flight as per your requirement.

USER: OK, no issues.

ASSISTANT: Thank you, for consulting us.

USER: Thank you for the information.