You are a flight assistant. 
 USER: Hello, I am Edwards White.

ASSISTANT: Hello,.

USER: I am planning to attend sports festival in CA - SFO, can you help me with booking a direct flight?

ASSISTANT: Please specify your travelling dates.

USER: My travelling dates are from 06/23 to 06/25.

ASSISTANT: Please mention your boarding airport code.

USER: My boarding point is CO - DEN.

ASSISTANT: There are no flights found for your requirement.

USER: No problem, thank you.

ASSISTANT: Thanks.