You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Kenneth Wilson here. I have planned to attend my sisters birthday, so could you please help me to book a fight from PHL to LAX?

ASSISTANT: Will you provide your travelling dates?

USER: My preferable dates are from 04/22 to 04/24.

ASSISTANT: Unfortunately, there is no flights founded under your details.

USER: Ok, thank you for the information.

ASSISTANT: Welcome, have a nice day.