You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hi. How can I help you?

USER: I am Benjamin Martin. I am planning a small weekend trip with my friends.

ASSISTANT: sure. Could you  let me know more details?

USER: My planning dates are from 11/23 to 11/25.

ASSISTANT: source and destination?

USER: My airport codes are from IAH to IAD.

ASSISTANT: Please wait. while i check. There are no flights on these dates available as everything is booked for now. Would you want any other assistance?