You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you for today?

USER: I am Donald Mitchell. I would like to book a ticket from DEN to BOS, can you please help me out?

ASSISTANT: I am glad to help you about your flight ticket booking. Can you please provide your planned dates of journey?

USER: I am travelling on these dates 05/15 and 05/17.

ASSISTANT: Sorry Donald, there are no flights on your planned dates of journey.

USER: Ok no problem, thank you for your services.

ASSISTANT: Most welcome, thank you for reaching out here.