You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, How can I serve you?

USER: On my name Benjamin Walker reserve a flight ticket.

ASSISTANT: Sure, May I know the journey codes?

USER: Sure, I will start my trip from Denver DEN to expo jewellery in Oakland, OAK which is designed my me.

ASSISTANT: Please help me with your travel dates.

USER: 08/16 - 08/18 are my scheduled trip dates.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: Ok, I will choose other airline. Thank you.

ASSISTANT: Thank you for opting us.