filesystem api delete file or folder

gistfile1.js

// delete file
function deleteFile(fileName){
  fs.root.getFile(fileName, {create: false}, function(fileEntry) {
		fileEntry.remove(function() {
			displayDirectory();
		}, errorHandler);
	}, function(e) {
		if (e.code == FileError.INVALID_MODIFICATION_ERR){
			alert('Filename does not exists');
		}
	});
}

// delete folder
function deleteFolder(fileName){
	fs.root.getDirectory(fileName, {create: false}, function(dirEntry) {
		dirEntry.removeRecursively(function() {
			displayDirectory();
		}, errorHandler);
	}, function(e) {
		if (e.code == FileError.INVALID_MODIFICATION_ERR){
			alert('Folder does not exists');
		}
	});
}