Google Translate API: Set default language as spanish in JavaScript

hello,

I am using google translation widget and i want when website open it should auto select spanish as default language.

i am using following code but its not working.

please check and advice.

<div id="google_translate_element"></div>
<%--//if you want to set default language add this--%>
<script type="text/javascript" src="//translate.google.com/translate_a/element.js?cb=googleTranslateElementInit"></script>
<script type="text/javascript">
    function googleTranslateElementInit() {
        setCookie('googtrans', '/en/es', 1);
        new google.translate.TranslateElement({ pageLanguage: 'ES', layout: google.translate.TranslateElement.InlineLayout.SIMPLE }, 'google_translate_element');
    }
    function setCookie(key, value, expiry) {
        var expires = new Date();
        expires.setTime(expires.getTime() + (expiry * 24 * 60 * 60 * 1000));
        document.cookie = key + '=' + value + ';expires=' + expires.toUTCString();
    }
</script>