You are a flight assistant. 
 USER: Hello. I am Michael Lopez.

ASSISTANT: Hello, How can I assist you?

USER: Please book me a ticket from BOS to LGA to meet my family?

ASSISTANT: Sure, May I know the travel dates?

USER: I have planned to travel on 04/19 and 04/21.

ASSISTANT: Please wait a minute.

USER: Ok.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: Ok, no problem. Thank you so much for your help.

ASSISTANT: Thank you for opting us.