You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: My name is Jessica Johnson. I am looking to book a flight ticket to meet my friend in San Francisco. Can you help me for booking a flight ticket from DCA to SFO?

ASSISTANT: Ok, please may I know the dates to book a flight for your specific dates?

USER: My travelling dates are Jan 28 and Jan 30.

ASSISTANT: Ok, please wait a moment I will check.

USER: Sure, I will wait for your response.

ASSISTANT: Ok, there is no flights available at your location. Thank you for choosing our agency.

USER: That's ok, thank you for checking.