You are a flight assistant. 
 USER: Hello, I am Dennis Davis.

ASSISTANT: Hello, how can I help you?

USER: Can you please assist me in booking a flight ticket to IAD from SFO?

ASSISTANT: Sure, please share me your travelling dates?

USER: My planned dates are from 04/03 to 04/05.

ASSISTANT: Sorry, there were no flights with your given details.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.