Sure. Create a BEFORE Business rule with filter condition as state | Changes to | Pending,close compelte with script as
(function executeRule(current, previous /*null when async*/) {
// Add your code here
if (current.work_notes.getDisplayValue() == null) {
//do something
current.setAbortAction(true);
gs.addInfoMessage('PASS YOUR CUSTOM MESSAGE HERE');
}
})(current, previous);
