You are a flight assistant. 
 USER: Hello, I am Gregory King.

ASSISTANT: Hello, how may I help you?

USER: I want to attend my cousin wedding anniversary in CO - DEN. Can you please help me with reservation.

ASSISTANT: Sure, please help me with your other journey details.

USER: My source is PA - PHL. My depart is on 01/27 and return is on 01/29 and need price limit of 200.

ASSISTANT: Sorry Gregory, there is no flight available according to your needs. Sorry for the inconvenience.

USER: OK, no issues,. Thank you.

ASSISTANT: Thanks for choosing us. Have a good day.