custom function in MATE

$javascript1 = '
            <script type="text/javascript">
                    function md1()
                    {
                        alert("Mukesh");
                    }
            </script>';
echo $javascript1;

$userButtons[] = array(
    'button_html' => '<button onclick="md1();">Custom Button</button>'
);

$this->Editor->setConfig('userButtons',$userButtons);