alert function cann't work in watch list?

[YON]

I added an EFS formula with "alert.addtolist function" as a columns in watch list.
like this:

function preMain(){
}

function main(){
Alert.addToList( getSymbol(), "hello", Color.green, Color.black );
return;
}

but I cann't get result in EFS Alerts List.
What's wrong with this?

Thanks.
YON