You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Justin Campbell.

ASSISTANT: Justin, how may I help you?

USER: I just need your help in making my reservation from IAD to OAK.

ASSISTANT: Sure, please share your itinerary dates.

USER: My preferable travelling dates are from 04/26 to 04/28. I need 0 connected flight.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: Sorry Justin, no airlines is providing a direct flight from IAD to OAK on your preferred dates. Do you want to travel on some other day?

USER: It's ok, thank you.

ASSISTANT: Thank you for contacting us.