You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How could I aid you today?

USER: I am Timothy Johnson and I want to book a flight ticket to attend a my grand parent 60th anniversary at DC-IAD from TX-DFW.

ASSISTANT: Sure, At what dates would you like to depart and arrival?

USER: My travelling dates are from 06/14 to 06/18.

ASSISTANT: Ok, Wait a minute.

USER: Ok.

ASSISTANT: Thank you for waiting. There are no flights found based on your travelling dates. Thank you for connecting with us, Have a great day.

USER: No issue, thank you.