private void خروجToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }

private void فایلجدیدToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (saveFileDialog1.ShowDialog() == DialogResult.OK)
            { 
                System.IO.File.WriteAllText(saveFileDialog1.FileName,txtmatn.Text);
            }
        

public partial class Form1 : Form
    {
        string filename = "";

private void بازکردن ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (saveFileDialog1.ShowDialog() == DialogResult.OK)
            {
                System.IO.File.WriteAllText(saveFileDialog1.FileName, txtmatn.Text);
                filename = saveFileDialog1.FileName;
            }
        }

public partial class Form1: Form
    {
        string filename = "";
        bool seved = true;

private void فایلجدیدToolStripMenuItem_Click(object sender,EventArgs e)
        {
            if (saveFileDialog1.ShowDialog() == DialogResult.OK)
            {
                System.IO.File.WriteAllText(saveFileDialog1.FileName,txtmatn.Text);
                filename = saveFileDialog1.FileName;
                seved = true;
            }
        }

private void ذخیرهToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (filename == "")
            {
                if (saveFileDialog1.ShowDialog() == DialogResult.OK)
                {
                    System.IO.File.WriteAllText(saveFileDialog1.FileName, txtmatn.Text);
                    filename - saveFileDialog1.FileName;
                    saved = true;
                }
            }
        }

            else
            {
                System.IO.File.WriteAllText(filename, txtmatn.Text);
                saved = true;
            }
        }

private void بازکردنToolStripMenuItem_Click(object sender, EventArgs e)
     {
         if (saved == false)
         {
             DialogResult dr = new DialogResult();
             dr = MessageBox.Show("آیا میخواهید ذخیره کنید.", "اخطار", MessageBox.YesNoCancel);
             if (dr == DialogResult.Yes)
             {
                 if (filename == "")
                 {
                     if (saveFileDialog1.ShowDialog() == DialogResult.OK)
                     {
                      System.IO.File.WriteAllText(saveFileDialog1.FileName,txtmatn.Text);
                      filename = saveFileDialog1.FileName;
                      saved = true;
                     }   
                 }
                 else
                 {
                     System.IO.File.WriteAllText(filename, txtmatn.Text);
                     
                     saved = true;
                 }
             }
          }

if (dr == DialogResult.No)
          {
                   if (openFileDialog1.ShowDialog() == DialogResult.OK)
                   {
                    txtmatn.Text = System.IO.File.ReadAllText(openFileDialog1.FileName);
                    filename = openFileDialog1.FileName;
                    saved = true;
                   }
                   else
                   { 
                    if (openFileDialog1.ShowDialog() == DialogResult.OK)
                     {
                     txtmatn.Text = System.IO.File.ReadAllText(openFileDialog1.FileName);
                     filename = openFileDialog1.FileName;
                     saved = true;
                 }

else
           {
               if (openFileDialog1.ShowDialog() == DialogResult.OK)
               {
                   txtmatn.Text = System.IO.File.ReadAllText(openFileDialog1.FileName);
                   filename = openFileDialog1.FileName;
                   saved = true;
               }
                
                
           }
        }        
   }

private void textBox1_TextChanged(object sender, EventArgs e)
        {
            seved = false;
        }

private void فایلجدیدToolStripMenuItem1_Click(object sender, EventArgs e)
        {
            txtmatn.Text = "";
            filename = "";
            seved = true;
        }