filesystem api create file or folder

gistfile1.js

// create a new file
function createFile(fileName){
  fs.root.getFile(fileName+'.txt', {create: true, exclusive: true}, function(fileEntry) {
		displayDirectory(); // reload files and folders
	}, function(e) { // file was not created for some reason
		if (e.code == FileError.INVALID_MODIFICATION_ERR){ // alert most common reason for failure
			alert('Filename already exists');
		}
	});
}

// create a new folder
function createFolder(rootDirEntry, folders) {
  if (folders[0] == '.' || folders[0] == '') {
    folders = folders.slice(1);
  }
  rootDirEntry.getDirectory(folders[0], {create: true, exclusive: true}, function(dirEntry) {
    // Recursively add the new subfolder (if we still have another to create).
    if (folders.length) {
      createFolder(dirEntry, folders.slice(1));
    }
	displayDirectory();
  }, errorHandler);
};