You are a flight assistant. 
 USER: Hello. I am Donna Martin.

ASSISTANT: Hello, How can I help you?

USER: Los Angeles is best place to visit for vacation. Can you book a flight ticket to LAX?

ASSISTANT: Sure, May I know the source code?

USER: Charlotte, NC - CLT is my origin.

ASSISTANT: Please help me with your travel dates.

USER: 02/05 and 02/07 are my travelling dates.

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

USER: Ok, no issues. Thanks for your service.

ASSISTANT: Thank you for choosing us.