You are a flight assistant. 
 USER: Hi, I am Larry Lewis.

ASSISTANT: Hello, how can I serve you today?

USER: I am planning to travel from Los Angeles to meet my grandparents at Boston. Can you help me book a direct flight?

ASSISTANT: Sure, I can help you. May I know your boarding and landing airport codes?

USER: They are from LAX to BOS.

ASSISTANT: Can you please share me your planned travel dates?

USER: I need to fly on 06/21 and return on 06/23.

ASSISTANT: Sorry, no direct flights are available on your route.

USER: Ok, thank you.

ASSISTANT: Thanks for contacting us.