Arduino UNO + Ethernet shield + connection with authentication

Hi all,
I need to let arduino UNO connect via ethernet to a web page with authentication.
I tried to use the EthernetClient library with the base authentication, but i received the error:

connecting…
http://192.168.1.181/SystemLog.htm
QWRtaW46MDEyMzQ1
connected
HTTP/1.1 401 Unauthorized
WWW-Authenticate: Basic realm=“Protected”
Connection: close

401 Unauthorized: Password required

disconnecting.

Can you give me some advice? Here is my sketch:
thank you

#include <SPI.h>
#include <Ethernet.h>

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress server(192,168,1,181);

IPAddress ip(192,168,1,255);

EthernetClient client;

void setup() {
 Serial.begin(9600);
  while (!Serial) {
   ; // wait for serial port to connect. Needed for Leonardo only
 }

 // start the Ethernet connection:
 if (Ethernet.begin(mac) == 0) {
   Serial.println("Failed to configure Ethernet using DHCP");
   // no point in carrying on, so do nothing forevermore:
   // try to congifure using IP address instead of DHCP:
   Ethernet.begin(mac, ip);
 }
 // give the Ethernet shield a second to initialize:
 delay(1000);
 Serial.println("connecting...");
 Serial.println("http://192.168.1.181/SystemLog.htm");
 Serial.println("QWRtaW46MDEyMzQ1");

 // if you get a connection, report back via serial:
 if (client.connect(server, 80)) {
   Serial.println("connected");
   // Make a HTTP request:
   //client.println("GET /search?q=arduino HTTP/1.1");
   client.println("POST /SystemLog.htm");
   client.println("Host: 192.168.1.181");
   client.println("Authorization: Basic QWRtaW46MDEyMzQ1");
   client.println("Connection: close");
   client.println();
 } 
 else {
   // kf you didn't get a connection to the server:
   Serial.println("connection failed");
 }
}

void loop()
{
 // if there are incoming bytes available 
 // from the server, read them and print them:
 if (client.available()) {
   char c = client.read();
   Serial.print(c);
 }

 // if the server's disconnected, stop the client:
 if (!client.connected()) {
   Serial.println();
   Serial.println("disconnecting.");
   client.stop();

   // do nothing forevermore:
   while(true);
 }
}

I guess that's because the server doesn't know a user "Admin" with password "012345" (that's what is encoded into "QWRtaW46MDEyMzQ1").

solved, the username/password were wrong. tnx