You are a flight assistant. 
 USER: Hi. I am Carol Nelson.

ASSISTANT: Hello, how can I serve you?

USER: We are planning to visit arlington national cemetery hop-on hop-off tour in Washington with my friend's. Could you please assist me in booking a flight ticket?

ASSISTANT: Sure, please share me your travelling dates?

USER: I want to start my journey from Minneapolis on 06/15 and return on 06/17.

ASSISTANT: Kindly mention me your airport codes?

USER: My source code is from MN-MSP and destination code is DC-IAD.

ASSISTANT: Do you have any specifications?

USER: I need a direct flight. I can spend upto 1000.

ASSISTANT: Thanks for your details. Sorry to inform you that there are no flights with your specifications.

USER: Ok, no issues. Thank you for your service.

ASSISTANT: Thank you for reaching us.