I'm using the following script to translate a website.

    <div id="google_translate_element"></div>

    <script src="//translate.google.com/translate_a/element.js?cb=googleTranslateElementInit"></script>


    <select class="select-language" onchange="ChangeLang(this.value)">

        <option value="pt">Português</option>

        <option value="en">Inglês</option>

        <option value="es">Espanhol</option>

        <option value="it">Italiano</option>

        <option value="de">Alemão</option>

        <option value="fr">Francês</option>

    </select>

E

function ChangeLang(a) {
    var b, elemento = "";
    if (document.createEvent) {
        var c = document.createEvent("HTMLEvents");
        c.initEvent("click", true, true)
    }
    if (a == 'pt') {
        elemento = $(".goog-te-banner-frame:eq(0)").contents().find("button[id*='restore']")
    } else {
        switch (a) {
            case 'de':
            b = "alem";
            break;
            case 'es':
            b = "espanhol";
            break;
            case 'fr':
            b = "fran";
            break;
            case 'en':
            b = "ing";
            break;
            case 'it':
            b = "italiano";
            break
        }
        elemento = $(".goog-te-menu-frame:eq(0)").contents().find("span:contains('" + b + "')");
    }
    if (elemento.length > 0) {
        if (document.createEvent) {
            elemento[0].dispatchEvent(c)
        } else {
            elemento[0].click()
        }
    }
}
function googleTranslateElementInit() {
    new google.translate.TranslateElement({
        pageLanguage: 'pt',
        autoDisplay: false,
        includedLanguages: 'de,es,fr,en,it',
        layout: google.translate.TranslateElement.InlineLayout.SIMPLE
    },
    'google_translate_element');
}

The files are being called, no error is generated, and the translation does not occur.

@edit Testing with onclick instead of onchange works as expected.