You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I assist you today?

USER: Can you please help me in booking my flight ticket from SFO to DEN?

ASSISTANT: Sure, can you please share your journey dates?

USER: My planned travel dates are April 20-22.

ASSISTANT: Are you looking for any preferred connections?

USER: I prefer to fly in connected flight.

ASSISTANT: Do you have any other specifications to be met?

USER: I want to return in the evening.

ASSISTANT: Can I have your name to proceed further?

USER: Myself, Matthew Turner.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Thank you for your valuable time, unfortunately no flights available on that route.

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

ASSISTANT: Thank you for reaching us.