You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I be of your help?

USER: I am Kevin Brown and I want to book a direct flight  on 10/25 .

ASSISTANT: Sure, May I know the travelling dates? Can you provide your airport codes?

USER: My travelling dates are 10/23 to 10/25. CA-SFO and CO-DEN are my airport codes.

ASSISTANT: Let me know the price limit?

USER: 200 is my price.

ASSISTANT: We could not find any direct flight based on your data.

USER: No issue.

ASSISTANT: Thanks for reaching us. Have a nice day.

USER: Thank you for your help.