You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I serve you today?

USER: I am Robert Martin.

ASSISTANT: Ok.

USER:  I made a reservation earlier to go for a holiday trip with my friends, due to some financial problems I want to change my existing reservation. Can you help me in changing reservation?

ASSISTANT: Sure, We are here to help you. Please wait a while.

USER: Sure.

ASSISTANT: Thanks for being waiting.

USER: Ok.

ASSISTANT: We didn't found any reservation by this name.

USER: Ok, No problem. Thank you.

ASSISTANT: Thank you for choosing us.