You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Kenneth Perez here.

ASSISTANT: How can I help you Perez?

USER: I want to visit Washington, can you please reserve my ticket from OAK to IAD?

ASSISTANT: May I know your travelling dates?

USER: Sure, my preferable dates of journey is from 12/08 to 12/10.

ASSISTANT: Sorry Perez, no flight found on your route OAK to IAD.

USER: Ok, that's fine.

ASSISTANT: Thank you for contacting us.

USER: Thank you for your appreciable service.