Customising 'Export Layers to Files' Naming

Does the following code snippet work as expected to create the desired name? I.E. is the pop-up alert dialog showing the correct name?

//////////////
// Select front layer
app.activeDocument.activeLayer = app.activeDocument.layers[0];
// Group Name
var groupName = app.activeDocument.activeLayer.name;
// Select back layer
var backLayer = app.activeDocument.layers.length - 1;
var selectLayer = app.activeDocument.layers[backLayer];
app.activeDocument.activeLayer = selectLayer;
// Product Name
var productName = app.activeDocument.activeLayer.name;
// Combined name
var nameCombo = groupName + '_' + productName;
alert(nameCombo);
//////////////

I would agree that where name are built. You need the set the additional name components in there.