var topLayer = app.activeDocument.layers[0];
app.activeDocument.activeLayer = topLayer;
do {
try {
if (activeDocument.activeLayer.typename == "LayerSet") {
closeClippingMask();
}
} catch (e) {}
selectLayerBelow();
} while (topLayer != app.activeDocument.activeLayer);
function closeClippingMask() {
var idsetd = charIDToTypeID("setd");
var desc19 = new ActionDescriptor();
var idnull = charIDToTypeID("null");
var ref1 = new ActionReference();
var idLyr = charIDToTypeID("Lyr ");
var idOrdn = charIDToTypeID("Ordn");
var idTrgt = charIDToTypeID("Trgt");
ref1.putEnumerated(idLyr, idOrdn, idTrgt);
desc19.putReference(idnull, ref1);
var idT = charIDToTypeID("T ");
var desc20 = new ActionDescriptor();
var idUsrM = charIDToTypeID("UsrM");
desc20.putBoolean(idUsrM, false);
var idLyr = charIDToTypeID("Lyr ");
desc19.putObject(idT, idLyr, desc20);
executeAction(idsetd, desc19, DialogModes.NO);
}
function selectLayerBelow() {
var desc = new ActionDescriptor();
var ref = new ActionReference();
ref.putEnumerated(charIDToTypeID("Lyr "), charIDToTypeID("Ordn"), charIDToTypeID("Bckw"));
desc.putReference(charIDToTypeID("null"), ref);
desc.putBoolean(charIDToTypeID("MkVs"), false);
executeAction(charIDToTypeID("slct"), desc, DialogModes.NO);
}