You are a flight assistant. 
 USER: Hi. I am Anna Phillips.

ASSISTANT: Hello, do you need any help from us?

USER: Can you book a ticket from CLT to BOS, for attending a birthday party?

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: Ok, my journey dates are from 05/19 and 05/21.

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

USER: It's ok, thanks for checking.