You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Gregory Evans.

ASSISTANT: How may I aid you?

USER: I am planning to attend music concert at EWR, can you please help me with booking a flight ticket from SFO?

ASSISTANT: Sure, when are you planning to depart and return on?

USER: Sure, I would like to depart on July 23 and return on July 25.

ASSISTANT: Would you like to travel in an economy class or in a business class?

USER: I prefer economy class.

ASSISTANT: Sorry, there is no flight found on your route.

USER: Ok, no issues. Thank you for checking.

ASSISTANT: Thanks for choosing us.

USER: You are welcome.