You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How can I help you?

USER: I am Margaret Clark .

ASSISTANT: OK.

USER: I would like to book a flight ticket from DCA to LAS.

ASSISTANT: Sure, could you please provide me travelling dates?

USER: Yes just a second .

ASSISTANT: OK.

USER: My travel dates are 07/07 to 07/09.

ASSISTANT: OK, can I know is there any price limit?

USER: And my costing is 1000 with 1 connection .

ASSISTANT: OK. Give me a moment. Sorry to inform you that there is no flight matching your criteria.

USER: OK . Thank you .

ASSISTANT: Thank you for reaching us.