function email_focus(email_field) {
    email_field.style.color = '#555';
    if (email_field.value == 'enter your e-mail address') {
        email_field.value = '';
    }
}
function email_blur(email_field) {
    if (email_field.value == '') {
        email_field.value = 'enter your e-mail address';
        email_field.style.color = '#818181';
    } else {
        email_field.style.color = '#555';
    }
}
function submit_subscribe_form() {
    document.getElementById('subscribe_form').submit();
}