You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am David Scott, want to travel from LGA to PHL.

ASSISTANT: On which dates you are willing to travel?

USER: My travelling dates are from 12/21 to 12/23. Please check the flight with 1 connection.

ASSISTANT: Sorry, there is a no flight available.

USER: It's ok, thank you.

ASSISTANT: Welcome.