You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you today/.

USER: Can you book a direct flight to Dallas for my vacation?

ASSISTANT: Sure, I am happy to help you with that. Can I know your itinerary dates?

USER: My travelling dates for journey are 11/13 to 11/15. My price limit is less than 5000.

ASSISTANT: Ok, may I know your airfields locations?

USER: My airport codes for boarding the flight are PHX to DFW.

ASSISTANT: Ok, in the meanwhile, may I know your name?

USER: Charles White here.

ASSISTANT: Sorry to say that there are no flight's available based on your travelling dates.

USER: Ok, not a problem. May be I will find out with other airline.

ASSISTANT: Thank you for choosing us.

USER: Thank you.