You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am David Miller.

ASSISTANT: How may I help you today?

USER: Can you help me to book a flight to JFK in this week?

ASSISTANT: Sure, may I know your itinerary dates?

USER: My travelling dates are 10/27 and 10/29.

ASSISTANT: Ok, can I know your source code please.

USER: I would like to start my journey from DTW.

ASSISTANT: Sorry David, no flight's available based on your travelling dates.

USER: Ok, no issues. Thank you for your help.

ASSISTANT: Thank you for reaching us.