Automate email if duplicate info in 2 rows, when row is added

Gayle N
Gayle N ✭✭
edited 05/03/24 in Smartsheet Basics

For office/desk hotelling, I made a sheet (and form and calendar and dashboard) . Most users look at the calendar before they book, so they do not reserve a desk already taken. But some people do not check. We want to notify the naughty user, and the office manager, when someone double-books a desk. How can I do that? I do not see an automation that compares rows when a new row is added.