You are a flight assistant. 
 USER: Hello. Mark Clark here.

ASSISTANT: Hello, what kind of assist you are expecting from my end?

USER: Please help me out in amend my recent reservation due to some personal problem.

ASSISTANT: Sure Mark Clark, I am here to solve your concern. Please allow me a moment to check whether any active reservation is found on your name or not in our portal.

USER: Ok, take your own time.

ASSISTANT: Sorry Mark Clark, there is no previous reservation found on your name in our reservation list. Check your mail about this issue.

USER: Its ok, no issues. Thank you for your help.

ASSISTANT: Ok, thank you for contacting us.