You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I render you today?

USER: Can you help me to change my recent reservation because my health condition was not good?

ASSISTANT: Sure, may I know your good name?

USER: I am Jason Walker.

ASSISTANT: Please wait for a minute.

USER: Sure, take your own time.

ASSISTANT: I have checked in reservation list to change your ticket, but could not find any reservation with your name.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for choosing us.