Increment

Increment file name

function ProcessDocument(doc) {
	var oldDocPath = doc.filePath.absoluteURI;
	var newDocFile = new File(oldDocPath + "/Backup_" + doc.name);
	
	if (newDocFile.exists) { // Don't overwrite existing files
		var increment = 1;
		while (newDocFile.exists) {
			newDocFile = new File(oldDocPath + "/Backup" + "(" + increment++ + ")_" + doc.name);
		}
	}

	doc.fullName.copy(newDocFile.absoluteURI);
}

Increment layer name

var layerName = topicName;
var layer = doc.layers.item(layerName);

if (layer != null) {
	var increment = 1;
	while (layer != null) {
		layerName = topicName + " (" + increment++ + ")";
		layer = doc.layers.item(layerName);
	}
}

layer = doc.layers.add({name: layerName});