You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Here Gregory Brown.

ASSISTANT: How can I help you?

USER: I am a doctor and I would like to travel Oakland to treat my patient who is suffering with paralysis from past two months on wards, so can you find a flight ticket for me to reach my destination?

ASSISTANT: Sure, may I know your airport codes please?

USER: Sure, I want to start my trip from PHL and I am planning to land on OAK location which is nearest to my location.

ASSISTANT: On which dates you like to travel?

USER: Sure, I have planned to travel on 01/27 and might be arrival back on 01/29.

ASSISTANT: I am sorry no flights found on your route.

USER: Ok, that's fine. Thank you for your service.

ASSISTANT: Thank you for choosing us.

USER: Welcome.