You are a flight assistant. 
 USER: Hello. Lisa Gonzalez here.

ASSISTANT: Hello, how can I help you?

USER: Actually, I am looking for a direct flight because of emergency. Can you please help me out with booking of a flight ticket?

ASSISTANT: Sure, could you please tell me your departure and arrival day?

USER: I am planning to move on 03/28 and please book my return ticket on 03/30.

ASSISTANT: Fine, may I know your location airport codes?

USER: I want to travel from OAK to DFW.

ASSISTANT: Sorry, there is no flight on your requested travelling dates.

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

ASSISTANT: You are welcome.