$wtsSendMessagesig = @'

     public static extern bool WTSSendMessage(

$wtsmessage = Add-Type -MemberDefinition $wtsSendMessagesig -name PSWTSSendMessage -Namespace GetLoggedOnUsers -PassThru

     $wtsmessage::WTSSendMessage($server, $element.SessionID,$messageTitle,$messageTitle.Length,$message,$message.Length,0,$timeout,[ref]$resp,$true)

static extern bool WTSSendMessage(

  Private Shared Function WTSSendMessage(ByVal hServer As IntPtr, ByVal SessionId As Int32, ByVal title As String, ByVal titleLength As UInt32, ByVal message As String, ByVal messageLength As UInt32, ByVal style As UInt32, ByVal timeout As UInt32, ByRef pResponse As UInt32, ByVal bWait As Boolean) As Boolean

    public static extern bool WTSSendMessage(

    result = WTSSendMessage(WTS_CURRENT_SERVER_HANDLE, WTS_CURRENT_SESSION, title, tlen, msg, mlen, 0, 0, out resp, false);

            public static extern bool WTSSendMessage(

                $MessageBox::WTSSendMessage(0, $sessionId, $title, $titleLength, $message, $messageLength, $buttonSet, $timeout, [ref] $response, $waitResponse)