You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Melissa Thomas, want to travel from CLT to OAK. Please help me.

ASSISTANT: Sure, may I know your trip dates please?

USER: My trip dates are from 06/28 to 06/30. Please check for only single connection.

ASSISTANT: Sorry, there is no flight available as per your request.

USER: That's fine, thank you.

ASSISTANT: Most welcome.