You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Rachel Martinez, planning to visit Boston to attend a seminar. Can you please book me a ticket from SFO to BOS?

ASSISTANT: Sure, may I know your trip dates?

USER: My preferable journey dates are from 05/03 to 05/05.

ASSISTANT: Sorry, there is no flight available as per your request.

USER: Ok, not an issue. I will find any alternate for this trip. Thank you for providing information.

ASSISTANT: Welcome.