I am running these 3 tests on Selenium ID,

but i want to run these tests in parallel on different browsers , for that i am trying to use Selenium Grid and referring this http://code.google.com/p/selenium/wiki/Grid2
for that i am using this code
public class testjava extends SeleneseTestCase {
@Before
public void setUp() throws Exception {
selenium = new DefaultSelenium("localhost", 4444, "*chrome", "www.yahoo.com/");
selenium.start();
}
@Test
public void testTestjava() throws Exception {
}
@After
public void tearDown() throws Exception {
selenium.stop();
}
}
but i am getting this exception
java.lang.NoSuchMethodError: org.apache.http.conn.scheme.Scheme.<init>(Ljava/lang/String;ILorg/apache/http/conn/scheme/SchemeSocketFactory;)V
at org.openqa.selenium.remote.internal.HttpClientFactory.getClientConnectionManager(HttpClientFactory.java:57)
at org.openqa.selenium.remote.internal.HttpClientFactory.<init>(HttpClientFactory.java:47)
at org.openqa.selenium.remote.HttpCommandExecutor.<init>(HttpCommandExecutor.java:211)
at org.openqa.selenium.remote.RemoteWebDriver.<init>(RemoteWebDriver.java:102)
at com.selenium.testjava.setUp(testjava.java:20)
at junit.framework.TestCase.runBare(TestCase.java:128)
at com.thoughtworks.selenium.SeleneseTestCase.runBare(SeleneseTestCase.java:230)
at junit.framework.TestResult$1.protect(TestResult.java:110)
at junit.framework.TestResult.runProtected(TestResult.java:128)
at junit.framework.TestResult.run(TestResult.java:113)
at junit.framework.TestCase.run(TestCase.java:120)
at junit.framework.TestSuite.runTest(TestSuite.java:228)
at junit.framework.TestSuite.run(TestSuite.java:223)
at org.junit.internal.runners.OldTestClassRunner.run(OldTestClassRunner.java:35)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:49)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Thanks