Try to create layers but nothing appends

[flapflap]

Here is my code

// CONFIG
var verbose=true; // Set verbose mode
var layerLabelsName="Labels"; // Name of layer for labels, if not find will be create
var layerLabelsId=-1; // The id of the layer for labels
var layerItemsName="Items"; // Name of layer where items will be placed, if not find will be create
var layerItemsId=-1; // The id of the layer for items
var folderAssetsName="Assets"; //Name of library folder for Assets, if not find will be create
var folderAssetsId=-1; // The id of the Assets folder
var frameExport=2; // Number of frame where items will be placed. If the Assets library folder have subfolders, each items will be create in a specific frame
// Make a echo action for trace that check verbose mode
function echo(msg){
	if(verbose){
		fl.trace(msg);
	}
}
// Methods used
// Check if an item is in a folder in the subFolders array
// @param item : reference to the item
// @return the id of the subfolder
function isInSubFolder(item){
	var subFolders_lg = subFolders.length;
	for(var i = 0; i<subFolders_lg; i++){
		if(item.name.indexOf(subFolders[i])>-1){
			return i;
		}
	}
	return null;
}
// MAIN
fl.outputPanel.clear ();
echo("-- CreateAsset Lib2Frame Starting --");
// Checking the layers
var timeline = fl.getDocumentDOM ().getTimeline();
var layers = timeline.layers;
var layers_lg= layers.length;
for(var i= 0; i<layers_lg; i++){
	if(layers[i].name==layerLabelsName){
		layerLabelsId = i;
	}else if(layers[i].name==layerItemsName){
		layerItemsId = i;
	}
}
if(layerItemsId==-1){
	layerItemsId = fl.getDocumentDOM ().getTimeline().addNewLayer(layerItemsName);
	echo("Creating layer for items : "+layerItemsName);
}
if(layerLabelsId==-1){
	layerLabelsId = fl.getDocumentDOM ().getTimeline().addNewLayer(layerLabelsName);
	echo("Creating layer for labels : "+layerLabelsName);
}

I don't get why my layer are not created... is you guys got some clue for me ?