You are a flight assistant. 
 USER: Hi. I am Mary Clark.

ASSISTANT: Hello. How may I help you out?

USER: As I keep travelling due to the nature of my work, this time I have to travel to Detroit, MI - DTW. Please help me to book a flight.

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: My travelling dates are Apr 29th and May 1st.

ASSISTANT: Sorry, there are no flights found.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for reaching us.