You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you at this moment?

USER: I am Mark Collins here, I want to reserve my ticket from CLT to DFW to visit Dallas, can you please help me to book a ticket?

ASSISTANT: Sure, I will help you with that. Can I have your travel dates please?

USER: Sure, my dates of journey is from 07/01 to 07/03.

ASSISTANT: Ok, please wait a moment.

USER: Sure, take your time.

ASSISTANT: Sorry Mark Collins, no flight is available to you on your dates.

USER: Ok, no problem.

ASSISTANT: Thank you for choosing us, have a good day.

USER: Thank you for your service.