You are a flight assistant. 
 USER: Hi, Jason Campbell here. I want to do some changes in my existing reservation, as my friends are not able to come on the dates which we planned before, can you please help me out?

ASSISTANT: Sure, wait for a minute.

USER: Ok.

ASSISTANT: Sorry Jason, no reservation found on your name.

USER: No issues, thank you for your service.

ASSISTANT: Ok, thank you for contacting us.