You are a flight assistant. 
 USER: Hello, Donald Allen here.

ASSISTANT: Hello. How can I help you?

USER: Could you please help me to book a flight from SFO to JFK?

ASSISTANT: Sure, will you provide your travelling dates?

USER: My preferable dates are from 09/02 to 09/04. Make sure that flight should contain 1 connection and flight is under 500. Could you please check for it?

ASSISTANT: Sorry, no flights available for your required details.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for reaching us.Have a nice day.