int main()
{
while (true) // Infinite loop
{
keybd_event(~YourKey~, 0, KEYEVENTF_KEYDOWN, 0); //Key Down
Sleep(1);
keybd_event(~YourKey, 0, KEYEVENTF_KEYUP, 0); //Key Up
}
}

Public Declare Function GetAsyncKeyState Lib "user32" (ByVal vKey As Long) As Integer
Class MainShizzle
'Declares
Public Declare Sub keybd_event Lib "user32" (ByVal bVk As Byte, ByVal bScan As Byte, ByVal dwFlags As Long, ByVal dwExtraInfo As Long)
Public Declare Function GetAsyncKeyState Lib "user32" (ByVal vKey As Long) As Integer
'Thread(s)
Dim thread_Spammer As New System.Threading.Thread(AddressOf Spammer)
'Vars
Const VK_RETURN As Byte = &HD
Const KEYEVENT_KEYUP As UInteger = &H2
Const Spammer_Key As Integer = &H20
Const SpammerEnabled As Boolean = True
Dim Exit_Thread As Boolean = False
'Sub-routines
Sub Main()
thread_Spammer.Start()
Application.Run
End Sub
Public Sub Spammer()
While(Not Exit_Thread)
If SpammerEnabled AndAlso GetAsyncKeyState(Spammer_Key) Then
keybd_event(VK_RETURN, 0, 0, 0)
Threading.Thread.Sleep(15)
keybd_event(VK_RETURN, 0, KEYEVENT_KEYUP, 0)
End If
Threading.Thread.Sleep(1)
End While
End Sub
End Class