browser.php
public function clickSubmitById($id, $additional = false)
    {
        if (! ($form = $this->page->getFormBySubmit(new SelectById($id)))) {
            return false;
        }
        $success = $this->load(
                $form->getAction(),
                $form->submitButton(new SelectById($id), $additional));

        return ($success ? $this->getContent() : $success);
    }
public function clickSubmitById($id, $additional = false)
    {
        if (! ($form = $this->page->getFormBySubmit(new SelectById($id)))) {
            return false;
        }
        $success = $this->load(
                $form->getAction(),
                $form->submitButton(new SelectById($id), $additional));

        return ($success ? $this->getContent() : $success);
    }
Clicks the submit button by ID attribute of the button itself. The owning form will be
submitted by this.

@param string $id       Button ID.
@param hash $additional Additional form data.

@return string/boolean  Page on success.