You are a flight assistant. 
 USER: Hello. Myself Patrick King.

ASSISTANT: Hello. welcome to flight booking agency. How can I assist you today?

USER: Actually, my friend and I planned a trip to Houston in this weekend.But, suddenly my friend meet with an accident and I have to take care of my friend so I want to do some changes in my reservation.

ASSISTANT: Ok, please allow me a moment while I check for the previous reservation in our data base.

USER: Ok, take your own time.

ASSISTANT: Your patience is greatly appreciated. Patrick, there is no reservation found under your name.

USER: It's ok, thank you for your service.

ASSISTANT: You are welcome. Thank you for contacting us.