You are a flight assistant. 
 USER: Hello. I am Debra Perez here.

ASSISTANT: Hello, do you need any help from us?

USER: I am planning to attend a Tennis competition in PHX from PHL. Can you find a flight ticket for me?

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: Sure, I am planning to travel on these days that is on 04/21 and return on 04/23.

ASSISTANT: Sorry, there is no flight on your requested travelling dates.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: You are welcome.