browser.php
public function clickSubmit($label = 'Submit', $additional = false)
    {
        if (! ($form = $this->page->getFormBySubmit(new SelectByLabel($label)))) {
            return false;
        }
        $success = $this->load(
                $form->getAction(),
                $form->submitButton(new SelectByLabel($label), $additional));

        return ($success ? $this->getContent() : $success);
    }
public function clickSubmit($label = 'Submit', $additional = false)
    {
        if (! ($form = $this->page->getFormBySubmit(new SelectByLabel($label)))) {
            return false;
        }
        $success = $this->load(
                $form->getAction(),
                $form->submitButton(new SelectByLabel($label), $additional));

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

@param string $label    Button label. An unlabeled button can be triggered by 'Submit'.
@param hash $additional Additional form data.

@return string/boolean  Page on success.