How do I make selenium (jUnit) switch between open windows?

When I click the button, the browser opens a new window, I look for the element in the open window and can not find it.

I think he has not changed to the new window and is still looking at the old window. Error:

  

org.openqa.selenium.NoSuchElementException: Unable to locate element

Code:

WebDriver iframe = navegador.switchTo().frame(navegador.findElement(By.name("topbar"))); 
WebElement link = iframe.findElement(By.id("user_role_link"));// procuro o elemento no Iframe
link.click();       // clico no botão

// abre uma nova janela

for(String winHandle : navegador.getWindowHandles()){      // alterna para a janela que esta aberta
    navegador.switchTo().window(winHandle);
}

//tento procurar o elemento

element = navegador.findElementByName("user_role/user_role_xid_find");
element.click();