You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am Jerry Young.

ASSISTANT: Glad to meet you Jerry Young.

USER: I am planning to visit my sister's wedding function from PHL to ORD.Can you help me to book a ticket?

ASSISTANT: May I know your travelling dates please?

USER: My travelling dates are 03/16 to 03/18.

ASSISTANT: I am sorry, there are no flights with your details.

USER: That's fine. Thank you.

ASSISTANT: Welcome.