You can obtain the TrackableName by referencing its TrackableBehaviour. See the DefaultTrackableEventHandler script for an example.

Here are some examples of how to read and write files using System.IO - http://forum.unity3d.com/threads/8864-How-to-write-a-file

I'd recommend using Application.persistentDataPath+"/" as the base of your path. That will resolve to the appropriate directory across device contexts.

http://docs.unity3d.com/Documentation/ScriptReference/Application-persistentDataPath.html

ok sorry fot the hassle but will this be writtne inside the DefaultTrackerEventHandler?

You can, though if you anticipate a lot of read / writes to the file, it would probably be a good idea to implement this in another script which inherits from MonoBehaviour and have it perform these operations within its update method - e.g. it would receive the trackable name and status from the event handler and then peform the file operation within its own update callback. That way the event handler isn't blocked w/ the file operation.

Is there any way you could show me an example? .....

tnanks for everything 

wrong post haha

Thank you David i wrote this code and it worked on my computer i wil test it on my phone see where it goes and after ill add the Datapath but for now it works thank you

import System;

import System.IO;

var fileName = "chips.txt";

class MyCoolObject extends MonoBehaviour {

    var myCoolInt : int;

    var myCoolFloat : float;

}

function Start() {

if (File.Exists(fileName)) {

Debug.Log(fileName+"already exists.");

return;

}

var sr = File.CreateText(fileName);

sr.WriteLine("Chips");

sr.Close();

}