You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: Myself William King.

ASSISTANT: Nice meeting you King.

USER: I have to go San Francisco for attending a summit meeting there, can you please book a flight ticket for me?

ASSISTANT: Sure, we are gleeful to help you.

USER: Thanks.

ASSISTANT: Can you please provide your preferable dates of travelling?

USER: I have meeting on 06/28 so I want to departure on 06/27 and please book my return ticket also on 06/29.

ASSISTANT: Sure, may I know your origin and destination airport codes to proceed further?

USER: I want to fly from DFW airport and destination airport is SFO because these two airports are very convenient for me to travel.

ASSISTANT: Ok, please wait a moment to check the flights availability and I will revert back to you.

USER: Ok.

ASSISTANT: According to your details, I have found a flight with few seats are remaining from Spirit airlines with one break in your journey with a minimum fare of 100 is available for you. Shall I proceed with this one?

USER: But I want a direct flight to San Francisco, can you please check once again is there any direct flight available in this route?

ASSISTANT: Sure, please be on hold to check for a direct flight.

USER: Ok.

ASSISTANT: Sorry to inform you that, there are no direct flights available in your locations with your requested dates of travelling.

USER: Oh! It's ok no problem, I will go with another airline service.

ASSISTANT: Sorry for the inconvenience.

USER: It's ok, thank you for your information.

ASSISTANT: Thank you for approaching us, hope you have satisfied with my service.

USER: I really appreciate all the hard work you’ve done to help me.

ASSISTANT: Most welcome.