using System.Runtime.InteropServices; 
  
  
         private const int APPCOMMAND_VOLUME_MUTE = 0x80000; 
         private const int APPCOMMAND_VOLUME_UP = 0xA0000; 
         private const int APPCOMMAND_VOLUME_DOWN = 0x90000; 
         private const int APPCOMMAND_MICROPHONE_VOLUME_MUTE = 0x180000; 
         private const int WM_APPCOMMAND = 0x319; 
   
         [DllImport("user32.dll")] 
         public static extern IntPtr SendMessageW(IntPtr hWnd, int Msg, IntPtr wParam, IntPtr lParam); 
         private void Sessiz() 
         { 
             SendMessageW(this.Handle, WM_APPCOMMAND, this.Handle, (IntPtr)APPCOMMAND_VOLUME_MUTE); 
         } 
         private void Mute() 
         { 
             SendMessageW(this.Handle, WM_APPCOMMAND, this.Handle, (IntPtr)APPCOMMAND_MICROPHONE_VOLUME_MUTE); 
         } 
         private void SesAzalt() 
         { 
             SendMessageW(this.Handle, WM_APPCOMMAND, this.Handle, (IntPtr)APPCOMMAND_VOLUME_DOWN); 
         } 
  
         private void SesYukselt() 
         { 
             SendMessageW(this.Handle, WM_APPCOMMAND, this.Handle, (IntPtr)APPCOMMAND_VOLUME_UP); 
         } 
  
  
  
         private void button1_Click(object sender, EventArgs e) 
         { 
             Mute(); 
         }