You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: Myself Christopher Martinez. Can you help me to book a flight ticket to PHL from EWR in the month of April?

ASSISTANT: Sure, please provide me your travelling dates to search a flight.

USER: Sure, my travelling dates are 04/18 and 04/20.

ASSISTANT: Sorry, I could not find any flight with your travel dates.

USER: Not a problem, anyway thank you for the information.

ASSISTANT: Thanks for choosing us, have a great day.