Help please [c# windowsforms hotkeys]

    [DllImport("user32.dll", SetLastError = true)]
        public static extern bool RegisterHotKey(
 
            IntPtr hWnd,    
            int id,    
            KeyModifiers fsModifiers,   
            Keys vk      
            );
        [DllImport("user32.dll", SetLastError = true)]
        public static extern bool UnregisterHotKey(
            IntPtr hWnd,    
            int id);     
 
             const int F11 = 0x0312;
             
             protected override void WndProc(ref Message message)
             {
                 if (message.Msg == F11)
                 {
                     timer1.Enabled = true;
                 }
                
                   

              
                 base.WndProc(ref message);
             }
 
 
        public enum KeyModifiers        //enum to call 3rd parameter of RegisterHotKey easily
        {
            None = 0,
            Alt = 1,
            Control = 2,
            Shift = 4,
            Windows = 8
        }

const int F11 = 0x0312;