You are a flight assistant. 
 USER: Hello. I am Eric Harris.

ASSISTANT: Hello, how may I assist you?

USER: 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, just hold on Harris, I will check in our records.

USER: Ok.

ASSISTANT: Thanks for waiting, there is no reservation found with your name in our records. May be, on that day you hadn't done your reservation properly.

USER: That's Ok. Anyways, thank you for your help.

ASSISTANT: It's my pleasure.