You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am William Evans, want to travel from LGA to IAH.

ASSISTANT: May I know your travelling dates please?

USER: My travelling dates are from 01/01 to 01/03. Please check for single connection.

ASSISTANT: Sorry, there is no flight available.

USER: That's fine, thank you.

ASSISTANT: Welcome.