You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I planned to meet my cousin in LAS, can you please help me to book a flight ticket from IAD?

ASSISTANT: Sure, I am here to help you in booking. can you please share your travel dates?

USER: I prefer to travel on May 21 and May 23.

ASSISTANT: Ok, please mention your name.

USER: I am George Nelson.

ASSISTANT: Do you have any specification?

USER: I prefer to travel in a connecting flight.

ASSISTANT: Sorry, no flights are available on your preferable travel dates.

USER: Ok, no problem. Thank you for your information.

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