Clicking a button in htmlunit produces cast exception?

When I try to run the program everything works except clicking the button. When I click the button I get this exception: java.lang.ClassCastException: com.gargoylesoftware.htmlunit.html.HtmlButtonInput cannot be cast to com.gargoylesoftware.htmlunit.html.HtmlSubmitInput

public class Connect {
    public Connect(int port, String host) {
        WebClient webClient = new WebClient(BrowserVersion.FIREFOX_3/*, host, port*/);
        webClient.setJavaScriptEnabled(true);
        HtmlPage page = null;
        try {
            page = webClient.getPage("localhost/vote.php");
        } catch (IOException e) {
            e.printStackTrace();
        }
        HtmlForm button = page.getFormByName("voted");
        HtmlSubmitInput formSubmit开发者_开发技巧 = button.getInputByName("reward");//errors: java.lang.ClassCastException: com.gargoylesoftware.htmlunit.html.HtmlButtonInput cannot be cast to com.gargoylesoftware.htmlunit.html.HtmlSubmitInput
        page.executeJavaScript("setStatus(1);");
        page.executeJavaScript("setStatus(2);");
        page.executeJavaScript("setStatus(3);");
        page.executeJavaScript("canClickReward = true;");

        try {
            formSubmit.click();
        } catch (IOException e) {
            System.out.println("Form Button" + e.getMessage());
        }
        //page.executeJavaScript("document.forms[\"voted\"].submit()"); //Doesn't submit form
        System.out.println(page.asText());
    }
}

Does anyone know how I could fix the cast issue so it will click the button in the form?

---

Change the line

HtmlSubmitInput formSubmit = button.getInputByName("reward");

to

HtmlButtonInput formSubmit = button.getInputByName("reward");

The first line would work if your HTML had

<input type="submit" name="reward" .../>

But apparently it has

<input type="button" name="reward" .../>