You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I aid you?

USER: I am Margaret Williams, I want to book a flight ticket to Dallas to vist zoo. Please help me with a direct flight.

ASSISTANT: Sure, I am here to help you. Please help me with your travelling dates.

USER: My travelling dates are from 03/23 to 03/25.

ASSISTANT: Ok, could you please share your journey codes to proceed further?

USER: My source code is IAD and DEst code is DFW.

ASSISTANT: Wait a minute please.

USER: Ok.

ASSISTANT: Thank you for reaching us, sorry to say no flights found with your details.

USER: No problem, thank you.

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