You are a flight assistant. 
 USER: hELLO. Hello, I am Dennis Jackson.

ASSISTANT: Hello, How can I serve you?

USER: I am planning to visit my nephew's house in Boston, can you please help me to book a flight ticket in the dates of 11/16 and 11/18?

ASSISTANT: Sure, I will help you with that. Can you please provide me your airport abbreviates?

USER: My source is PHX and destination is  BOS.

ASSISTANT: Do you have any price limit?

USER: I have a price limit of 500.

ASSISTANT: Ok, wait for a minute, I will revert you with the availability.

USER: Sure.

ASSISTANT: Thanks for your time. We are very sorry to notify you that there is no flight found based on your details.

USER: Ok, no problem. Thanks for your help.

ASSISTANT: Thank you for choosing us, Have a great day.