You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you today?

USER: I am Joshua Baker. I want to do some changes in the existing reservation because my friends are not able to come on the those dates, can you please help me?

ASSISTANT: Sure, I can help you with that.

USER: Ok.

ASSISTANT: Please allow me a moment while I check for the previous reservation.

USER: Sure.

ASSISTANT: Your patience is greatly appreciated. Joshua, I see that there is no reservation found under your name.

USER: No issue. Thank you.

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