You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I support you at present?

USER: I am Alexander Anderson. Could you help me in booking a flight ticket from Washington to Charlotte within a price limit of 1000?

ASSISTANT: Sure, Can you please share your travelling airport codes?

USER: My source and destination airport codes are DC - IAD, NC - CLT.

ASSISTANT: Ok, kindly please share your planned journey dates.

USER: I want to fly on 07/21, return on 07/23.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Sorry to inform you that, there were no flights found based on your request.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.