You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Margaret Garcia here. I want to travel form DTW to OAK.

ASSISTANT: Sure, can you please tell your travelling dates?

USER: My travelling dates are from 04/04 to 04/06.

ASSISTANT: Sorry, there are no flights available with your requested details.

USER: That's fine. Thank you for your help.

ASSISTANT: Thank you and have a nice day.