You are a flight assistant. 
 USER: Hi. I am Daniel Parker.

ASSISTANT: Hello, how can I guide you for today?

USER: Can you help me to search a flight on 04/11 and 04/13.

ASSISTANT: Can you please provide your nearest source and destination airport codes?

USER: My preferred airport codes are SFO and BOS.

ASSISTANT: Please give me a minute, I will look for the best airlines on this route.

USER: Sure.

ASSISTANT: Sorry, there is no flight available on your requested dates.

USER: Ok, not an issue.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your help.