You are a flight assistant. 
 USER: Hi, I am Catherine Johnson.

ASSISTANT: Hello, How can I assist you?

USER: Could you please help me to book a flight ticket from Detroit, MI-DTW to reach Las Vegas, NV-LAS?

ASSISTANT: Sure, May I know the travel dates?

USER: I will depart on 07/23 and my return date would be on 07/25.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: No issues, I'll choose any alternative to reach my destination. Thank you for your information.

ASSISTANT: Thank you for reaching us.