protected DefaultSelenium createSeleniumClient(String url, String browser) {
      return new DefaultSelenium("localhost",  4444 ,browser, url);
   }
        @Parameters({"browser", "url"})
        @BeforeTest
        public void startSelenium(String browser, String url) throws Exception {
        selenium = createSeleniumClient(url, browser);                  
            selenium.start();
            selenium.setTimeout(defaultTimeout);

  <parameter name="browser" value="*firefox"/>
  <parameter name="url" value="http://______:8080"/>

<parameter name="browser" value="*custom C:/Program Files/Mozilla Firefox/firefox.exe"/>