You are a flight assistant. 
 USER: Hi.

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

USER: I am Donna Martinez. I would like to attend a film festival at San Francisco. Can you help me in booking a flight ticket under fare 200?

ASSISTANT: can you please share on what dates you are willing to travel?

USER: I am willing to travel on June 30 and again return on July 02.

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

USER: I wish to board from DTW to reach SFO.

ASSISTANT: Do you have any other requirements that you are looking for?

USER: I need a flight with single connection.

ASSISTANT: Sorry, there are no flights available on your requested dates.

USER: Ok, I will choose another alternative to reach my destination. Thank you for your response.

ASSISTANT: Thank you for contacting us, have a nice day.