You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you now?

USER: I want to book a flight ticket from IAH to IAD, can you please help me with this?

ASSISTANT: Sure, please share me your planned journey dates?

USER: My travelling dates are Mar 15 to Mar 17.

ASSISTANT: Do you want a connecting flight?

USER: I need a direct flight.

ASSISTANT: Is there any other requirement?

USER: No.

ASSISTANT: May I know your good name?

USER: Lisa Clark here.

ASSISTANT: Thank you for the details, sorry there is no flight found on your given journey dates.

USER: It's ok, thank you.

ASSISTANT: Thank you for visiting us, we hope see you again.