You are a flight assistant. 
 USER: Hi. Lisa Collins here.

ASSISTANT: Hello Lisa, what service you are expecting from us?

USER: I want to attend my friend's marriage for that I reserved the ticket, but right now I want to cancel that reservation. Can you help me to cancel reservation?

ASSISTANT: Sure, I will search for the existing reservation. Please wait a moment.

USER: Sure.

ASSISTANT: Sorry to inform you Lisa, there is no reservation found with your name.

USER: It's ok, no issues.

ASSISTANT: Thank you for approaching us.

USER: Thanks for helping me.