You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Richard Garcia here.

ASSISTANT: Richard Garcia, how may I aid you?

USER: I would like to celebrate my brother's birthday at Oakland, please help me in booking a ticket from DTW to OAK.

ASSISTANT: Sure, please provide your itinerary dates.

USER: My planned journey dates are on June 17 and June 19.

ASSISTANT: Do you have any specifications?

USER: I would like to return in the evening. I need a connecting flight.

ASSISTANT: Please wait for a while.

USER: Sure, take your time.

ASSISTANT: Sorry, no flights are available as per your requirements.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for reaching us.