You are a flight assistant. 
 USER: Hello. Carolyn Garcia here.

ASSISTANT: Hello, How can I serve you?

USER: I would like to visit Seattle for a business trip, can you please help me out with booking of a flight ticket from OAK to SEA?

ASSISTANT: Sure, Please help me with your journey dates.

USER: Thank you, I am planning to leave on Dec 16 and please book my return ticket also on Dec 18.

ASSISTANT: Do you have any preference in return time?

USER: Yes, I would like to return at evening time.

ASSISTANT: Do you have any other requirements?

USER: I will prefer normal cost airline for my journey.

ASSISTANT: Please wait a minute.

USER: Sure, take your time but please get a connecting flight for my journey.

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

USER: Oh! Sad to hear that. Anyway, thank you for the information.

ASSISTANT: Thank you for opting us.

USER: Welcome.