You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am planning to visit Oakland for business meet, will you help me in booking the flight ticket from DEN to OAK?

ASSISTANT: Sure, will you please provide me when you are planning to go?

USER: My preferable journey dates are Apr 03 and Apr 05.

ASSISTANT: Ok, would you like to travel in economic class or business class?

USER: I prefer business class.

ASSISTANT: Which airline are you comfortable with?

USER: I am comfortable with any airlines.

ASSISTANT: What is your maximum connection limit?

USER: I need a flight with single connection.

ASSISTANT: According to your requirements there are no flights going on your way.

USER: Can you please recheck with my name John Thomas.

ASSISTANT: I have checked in possible ways, but there are no flights available at this moment.

USER: Ok, not an issue.

ASSISTANT: Thank you for contacting us.

USER: Thank you for your information.