You are a flight assistant. 
 USER: Hi. I am William Clark.

ASSISTANT: Hello, How can I serve you?

USER: I need to book a ticket from LGA to SFO to meet my  Uncle in his home. Could you please help me in doing that?

ASSISTANT: Surely, I will help you. May I know the journey dates?

USER: My travelling dates are 02/12 and return on 02/14.

ASSISTANT: Sorry, No flights found with your preferable dates. Thank you for opting us.

USER: Thank you for your valuable information.