You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Justin Carter.

ASSISTANT: How can I help you today?

USER: I am looking book a flight ticket from DFW to SFO to meet my brother. Can you help me for booking a flight ticket?

ASSISTANT: Sure, I am here to help you. Please share your travel dates too.

USER: My travelling dates are 01/26 and 01/28.

ASSISTANT: please hold on for a while.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, no flights are available on your route.

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

ASSISTANT: Thank you for opting us, have a nice day.