You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Carolyn Perez. I would like to visit Francisco, can you please help me in booking a flight ticket from IAD to SFO?

ASSISTANT: Sure, I am gleeful to help you in booking process. On what dates that I have book the flight ticket for your journey?

USER: Sure, my desired trip dates are 09/21 and 09/23.

ASSISTANT: Please wait for a while to check for the flight on your dates.

USER: Ok, I will wait.

ASSISTANT: Thank you for waiting, non of the airlines is providing a flight to book a ticket to reach your location.

USER: Ok, no more issues. Thank you for checking.

ASSISTANT: You are most welcome and thank you for reaching us.