You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I am Michael Johnson, can you help me to change the reservation I did recently?

ASSISTANT: Sure, I will try to change your recent reservation, please wait for a minute.

USER: Ok, I will wait.

ASSISTANT: Sorry, I could not find any reservation with your name.

USER: Ok, not a problem. Thank you for assisting me.

ASSISTANT: My pleasure.