QWebElement evaluateJavaScript this.click() method

[CTpaHrep]

Hello folks.

I have the HTML form in QWebView loaded. This HTML has following two elements:

<button class="submit1" tabindex="1" type="submit" id="submit1">accept</butto
<button class="submit2" tabindex="2" type="submit" id="submit2">decline</button>

<button class="submit1" tabindex="1" type="submit" id="submit1">accept</butto
<button class="submit2" tabindex="2" type="submit" id="submit2">decline</button>

To copy to clipboard, switch view to plain text mode 

In code I have follwing:

QWebView webView;
...
QWebElement button = webView->page()->mainFrame()->documentElement().findFirst("button[id=\"submit1\"]");
button.evaluateJavaScript("this.click();");

QWebView webView;
...
QWebElement button = webView->page()->mainFrame()->documentElement().findFirst("button[id=\"submit1\"]");
button.evaluateJavaScript("this.click();");

To copy to clipboard, switch view to plain text mode 

And this last line of code don't work for me.
Moreover if I have an <input> element instead of button - JavaScript click() method works fine

[wysota]

Does button refer to a valid element before line #4?