You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I want to attend a seminar on automation, so please book my ticket from ORD to IAH.

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

USER: My itinerary dates are July 26 and July 28.

ASSISTANT: Ok, please mention your name.

USER: Dennis Harris here.

ASSISTANT: Do you have any specification?

USER: I want to depart in the afternoon.

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

USER: No problem, thank you.

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