Login en android

esta es la clase main:

public class MainActivity extends Activity {
EditText un,pw;
TextView error;
Button ok;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
un=(EditText)findViewById(R.id.et_un);
pw=(EditText)findViewById(R.id.et_pw);
ok=(Button)findViewById(R.id.btn_login);
error=(TextView)findViewById(R.id.tv_error);

ok.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub

ArrayList<NameValuePair> postParameters = new ArrayList<NameValuePair>();
postParameters.add(new BasicNameValuePair("email", un.getText().toString()));
postParameters.add(new BasicNameValuePair("password", pw.getText().toString()));
postParameters.add(new BasicNameValuePair("gestion","0"));
String response = null;
try {
response = CustomHttpClient.executeHttpPost("192.168.1.108/index.php", postParameters);
String res=response.toString();
res= res.replaceAll("\\s+","");
if(res.equals("1"))
error.setText("Correct Username or Password");
else
error.setText("Sorry!! Incorrect Username or Password");
} catch (Exception e) {
un.setText(e.toString());
}

}
});
}
}

clase HTTP:

public class CustomHttpClient {
/** The time it takes for our client to timeout */
public static final int HTTP_TIMEOUT = 30 * 1000; // milliseconds

/** Single instance of our HttpClient */
private static HttpClient mHttpClient;

/**
* Get our single instance of our HttpClient object.
*
* @return an HttpClient object with connection parameters set
*/
private static HttpClient getHttpClient() {
if (mHttpClient == null) {
mHttpClient = new DefaultHttpClient();
final HttpParams params = mHttpClient.getParams();
HttpConnectionParams.setConnectionTimeout(params, HTTP_TIMEOUT);
HttpConnectionParams.setSoTimeout(params, HTTP_TIMEOUT);
ConnManagerParams.setTimeout(params, HTTP_TIMEOUT);
}
return mHttpClient;
}

/**
* Performs an HTTP Post request to the specified url with the
* specified parameters.
*
* @param url The web address to post the request to
* @param postParameters The parameters to send via the request
* @return The result of the request
* @throws Exception
*/
public static String executeHttpPost(String url, ArrayList<NameValuePair> postParameters) throws Exception {
BufferedReader in = null;
try {
HttpClient client = getHttpClient();
HttpPost request = new HttpPost(url);
UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(postParameters);
request.setEntity(formEntity);
HttpResponse response = client.execute(request);
in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));

StringBuffer sb = new StringBuffer("");
String line = "";
String NL = System.getProperty("line.separator");
while ((line = in.readLine()) != null) {
sb.append(line + NL);
}
in.close();

String result = sb.toString();
return result;
} finally {
if (in != null) {
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}

/**
* Performs an HTTP GET request to the specified url.
*
* @param url The web address to post the request to
* @return The result of the request
* @throws Exception
*/
public static String executeHttpGet(String url) throws Exception {
BufferedReader in = null;
try {
HttpClient client = getHttpClient();
HttpGet request = new HttpGet();
request.setURI(new URI(url));
HttpResponse response = client.execute(request);
in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));

StringBuffer sb = new StringBuffer("");
String line = "";
String NL = System.getProperty("line.separator");
while ((line = in.readLine()) != null) {
sb.append(line + NL);
}
in.close();

String result = sb.toString();
return result;
} finally {
if (in != null) {
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}

este es el XML:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="210dip"
android:layout_marginTop="10dip"
android:background="#DDDDDD">
<TextView
android:id="@+id/tv_un"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="10pt"
android:textColor="#444444"
android:layout_alignParentLeft="true"
android:layout_marginRight="9dip"
android:layout_marginTop="20dip"
android:layout_marginLeft="10dip"
android:text="User Name:"/>
<EditText
android:id="@+id/et_un"
android:layout_width="150dip"
android:layout_height="wrap_content"
android:background="@android:drawable/editbox_background"
android:layout_toRightOf="@id/tv_un"
android:layout_alignTop="@id/tv_un"/>
<TextView
android:id="@+id/tv_pw"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="10pt"
android:textColor="#444444"
android:layout_alignParentLeft="true"
android:layout_below="@id/tv_un"
android:layout_marginRight="9dip"
android:layout_marginTop="15dip"
android:layout_marginLeft="10dip"
android:text="Password:"/>
<EditText
android:id="@+id/et_pw"
android:layout_width="150dip"
android:layout_height="wrap_content"
android:background="@android:drawable/editbox_background"
android:layout_toRightOf="@id/tv_pw"
android:layout_alignTop="@id/tv_pw"
android:layout_below="@id/et_un"
android:layout_marginLeft="17dip"
android:password="true" />
<Button
android:id="@+id/btn_login"
android:layout_width="100dip"
android:layout_height="wrap_content"
android:layout_below="@id/et_pw"
android:layout_alignParentLeft="true"
android:layout_marginTop="15dip"
android:layout_marginLeft="110dip"
android:text="Login" />
<TextView
android:id="@+id/tv_error"
android:layout_width="fill_parent"
android:layout_height="40dip"
android:textSize="7pt"
android:layout_alignParentLeft="true"
android:layout_below="@id/btn_login"
android:layout_marginRight="9dip"
android:layout_marginTop="15dip"
android:layout_marginLeft="15dip"
android:textColor="#AA0000"
android:text=""/>
</RelativeLayout>

trabajo en JAVA y me da el siguiente error al poner el email y el password:

Java.lang.illegalStateException:Target host must not be null or set in parameters scheme=null, host=null, path=212.227.59.52/settings/gestionj.php