C# basit müzik çalar yapımı

[DllImport("winmm.dll")]
       private static extern long mciSendString(string strCommand, StringBuilder strReturn, int iReturnLength, IntPtr hwndCallback);
       public string Pcommand;
       public bool isOpen;
 
 
       private void Form1_Load(object sender, EventArgs e)
       {
           timer1.Start();
        
       }
       string alarm;
       int cs = 0;
       private void timer1_Tick(object sender, EventArgs e)
       {
           label3.Text = DateTime.Now.ToLongTimeString();
           if (label3.Text == alarm)
           {
               MessageBox.Show("Alarm Çalıyor");
               Pcommand = "open \"" + textBox1.Text + "\" type mpegvideo alias MediaFile";
               mciSendString(Pcommand, null, 0, IntPtr.Zero);
               isOpen = true;
               Play(true);
               cs = cs + 1;
               if (cs.ToString() == textBox5.Text.ToString())
               {
                   Pcommand = "close MediaFile";
                   mciSendString(Pcommand, null, 0, IntPtr.Zero);
                   isOpen = false;
               }
           }
       }
      
       private void button1_Click(object sender, EventArgs e)
       {
           openFileDialog1.Filter = "Media File(*.mpg,*.dat,*.avi,*.wmv,*.wav,*.mp3)|*.wav;*.mp3;*.mpg;*.dat;*.avi;*.wmv";
           openFileDialog1.ShowDialog();
        
               textBox1.Text = openFileDialog1.FileName;
 
 
       }
 
       private void button2_Click(object sender, EventArgs e)
       {
           Pcommand = "open \"" + textBox1.Text + "\" type mpegvideo alias MediaFile";
           mciSendString(Pcommand, null, 0, IntPtr.Zero);
           isOpen = true;
           Play(true);
 
       }
 
       private void button3_Click(object sender, EventArgs e)
       {
           Pcommand = "close MediaFile";
           mciSendString(Pcommand, null, 0, IntPtr.Zero);
           isOpen = false;
 
       }
 
       private void button4_Click(object sender, EventArgs e)
       {
           this.Close();
       }
 
       public void Play(bool loop)
       {
           if (isOpen)
           {
               Pcommand = "play MediaFile";
               if (loop)
                   Pcommand += " REPEAT";
               mciSendString(Pcommand, null, 0, IntPtr.Zero);
           }
       }
    
       private void button5_Click(object sender, EventArgs e)
       {
           alarm = Convert.ToString(textBox2.Text + ":" + textBox3.Text + ":" + textBox4.Text);
       }