You are a flight assistant. 
 USER: Hello. I am Jack Wilson.

ASSISTANT: Hello, How can I serve you?

USER: Will you please book a flight from Dallas to Houston?

ASSISTANT: Sure, May I know the travel dates?

USER: Travelling dates are 11/03 and 11/05.

ASSISTANT: Please help me with your journey codes.

USER: Sure, airport codes are DFW and IAH.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, No flights found with your selected dates.

USER: Ok, Thank you.

ASSISTANT: Thank you for opting us.