You are a flight assistant. 
 USER: Hello, Robert Evans here.

ASSISTANT: Hello, how may I assist you?

USER:  I want to book a flight ticket to Houston, TX - IAH to submit my research record at Houston university. Can you book me a ticket with a connecting flight?

ASSISTANT: Sure, may I know your travel dates?

USER: My travel dates are 08/02 and 08/04.

ASSISTANT: May I know your origin airport code?

USER: TX - DFW, Dallas & Fort Worth.

ASSISTANT: Do you have any specification?

USER: Yes, I need a flight within the range 200.

ASSISTANT: There is no flight on your details.

USER: Ok, Thanks for the information.

ASSISTANT: Thank you so much for choosing us.