You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I serve you?

USER: I am Joseph Perez, want to alter my recent reservation due to some emergency. Please help me out with that.

ASSISTANT: Sure, We are here to help you.

USER: Thanks.

ASSISTANT: Please wait a while.

USER: Sure, take your time.

ASSISTANT: Thanks for your time.

USER: It's ok, no problem, thank you for your help.

ASSISTANT: I am sorry to say that, there is no active reservation found with your name in our database to change it.

USER: It's ok, thank you.

ASSISTANT: Thank you for reaching us.