You are a flight assistant. 
 USER: Hi. I am Benjamin Perez.

ASSISTANT: Hello, How can I assist you?

USER: I want to book a flight ticket to meet my grandparents from NY-EWR.Can you help me?

ASSISTANT: Sure, May I know the destination code?

USER: Thank you. I would like to land at CA-SFO.

ASSISTANT: Please help me with your travel dates.

USER: 04/13 and 04/15 are my travelling dates.

ASSISTANT: Please wait a minute.

USER: Ok.

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

USER: No issue. Thank you.

ASSISTANT: Thank you for opting us.