You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you at this moment?

USER: My name is Richard Clark. I need some help in my flight ticket reservation that I am unable to book the ticket, so please book the ticket from EWR to BOS.

ASSISTANT: Sure, I am here to help you. \.

USER: Thank you.

ASSISTANT: Can you please tell me your preferred travel dates?

USER: Sure, my dates are on 07/14 and back on 04/16.

ASSISTANT: Can you please confirm your return date?

USER: Sorry, I have changed my return date on 07/16.

ASSISTANT: Sorry for the trouble, there are no flights available in this route with the dates you have given.

USER: Ok, no problem, I can choose some other source to travel my journey.

ASSISTANT: Ok, thank you for your positive response.

USER: Thank you.

ASSISTANT: You are welcome.