You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Lisa Evans.

ASSISTANT: How can I help you today?

USER: I have a plan to meet my friend in Dallas, can you please help me for booking a flight ticket?

ASSISTANT: Sure, I will help you in booking. Can you please share your travel dates?

USER: My travelling dates are 05/04 and 05/06.

ASSISTANT: Ok, may I know your airport codes?

USER: I want to fly from DCA to DFW.

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

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

ASSISTANT: Welcome, have a nice day.