Cross thread error in filewatcher

Question

I have a problem here ;it's a filewatcher programm:
you enter a path in textbox,then go to that path and form example create or delete a folder then I want to log that
event

namespace filewatcherWFA
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }


        FileSystemWatcher fsw;

        public void WriteLog(string s)
        {
            // Get the Exact Location of the textFile
            string LogFilePath = Directory.GetParent(Application.ExecutablePath).ToString() + @"\Log.txt";

            //Create the StremWriter Object with FileName as Constuctor Argument and the Second Parameter is For

Weather Text is Appnded or Not
            StreamWriter sw = new StreamWriter(LogFilePath, true);

            sw.WriteLine(s);

            sw.Close();

          textBox2.Text = s+"\t";  //error occures here   ((Cross-thread)) !!

        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {

            string path=textBox1.Text;
            fsw = new FileSystemWatcher(path);
            label1.Visible = true;
            label1.Text = "path entered !";
            fsw.EnableRaisingEvents = true;
            fsw.IncludeSubdirectories = true;
            fsw.Deleted += new FileSystemEventHandler(fsw_Deleted);
            fsw.Created += new FileSystemEventHandler(fsw_Created);
        }

        void fsw_Created(object sender, FileSystemEventArgs e)
        {
            WriteLog("created File :" + e.FullPath);
        }

        void fsw_Deleted(object sender, FileSystemEventArgs e)
        {
            WriteLog("Deleted File :" + e.FullPath);
        }



    }
}

but when you are about to delete or create a folder it says::

<<Cross-thread operation not valid: Control 'textBox' accessed from a thread other than the thread it was created 

on.>>

how can I fix that error?