You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you with today?

USER: I would like to have a reservation in a flight from LGA to LAX, can you help me?

ASSISTANT: Sure, I can help you with that. can you please help me with your travelling dates?

USER: My dates are 04/10 to 04/20.

ASSISTANT: May I know your name to proceed further?

USER: Sure, my name is William Andreson.

ASSISTANT: Thank you for providing. William, I am sorry to inform you that there is no flight available at your requested dates.

USER: Ok, thanks for helping me.

ASSISTANT: You are welcome. Thank you for contacting us.