You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: I'm Paul Martinez.  I want to book a ticket from DTW to MSP to attend a workshop, can you help me?

ASSISTANT: Can I have your travelling dates?

USER: Ok, my preferable dates of journey are 11/28 and 11/30.

ASSISTANT: Sorry, there is no flight for you on your route.

USER: Ok, no problem. Thank you so much.

ASSISTANT: Ok, thanks for contacting us.