WebDriver script that avoids UnreachableBrowserException

gistfile1.java

import org.junit.Before;
import org.junit.Test;
import org.junit.After;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.By;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.support.ui.WebDriverWait;
import org.openqa.selenium.support.ui.ExpectedConditions;
import org.openqa.selenium.JavascriptExecutor;
import org.openqa.selenium.TimeoutException;
import org.openqa.selenium.NoSuchElementException;

public class IframeTest
{
	private WebDriver driver;

	@Before
	public void setUp() throws Exception
	{
		driver = new FirefoxDriver();
	}

	@Test
	public void test() throws Exception
	{
		driver.get( "http://www.baur.de" );
		switchToIframe( "layerEmailStart", "emailFormSubmit", 30000 );
		new WebDriverWait( driver, 30 )
			.until( ExpectedConditions.visibilityOfElementLocated( By.cssSelector( "input[type=\"submit\"]" )));
	}

	@After
	public void tearDown() throws Exception
	{
		driver.quit();
	}

	public void switchToIframe( String iframeId, String elementId, long maxWaitInMillis ) throws Exception
	{
		long startTime = System.currentTimeMillis();

		WebElement iframe = new WebDriverWait( driver, (int)( maxWaitInMillis / 1000 + 1 ) )
			.until( ExpectedConditions.visibilityOfElementLocated( By.xpath( "//iframe[@id='" + iframeId + "']" )));

		JavascriptExecutor js = (JavascriptExecutor) driver;
		
		String script = "var myIframe = document.getElementById( '" + iframeId + "' );"
						+ "var myIframeDoc = myIframe.contentDocument || myIframe.contentWindow.document;"
						+ "var myElement = myIframeDoc.getElementById( '" + elementId + "' );"
						+ "if ( !!myElement ) { return true; } else { return false; }";
		
		do
		{
			if (( Boolean )js.executeScript( script ))
			{
				driver.switchTo().frame( iframe );
				return;
			}
			Thread.sleep( 100 );
		}
		while ( System.currentTimeMillis() - startTime < maxWaitInMillis );
		
		throw new TimeoutException( "Timeout after " + ( System.currentTimeMillis() - startTime ) + " ms. Target was " + maxWaitInMillis + " ms.",
									new NoSuchElementException( "Could not locate element within iframe. Iframe ID: " + iframeId
										+ ". Element ID: " + elementId + "."));
	}
}