<pre class="lang:php title="Gravity Forms Submit button replace">
function schema_TinyMCE_init($in)
{
/**
* Edit extended_valid_elements as needed. For syntax, see
* http://www.tinymce.com/wiki.php/Configuration:valid_elements
*
* NOTE: Adding an element to extended_valid_elements will cause TinyMCE to ignore
* default attributes for that element.
* Eg. a[title] would remove href unless included in new rule: a[title|href]
*/
if(!empty($in['extended_valid_elements']))
$in['extended_valid_elements'] .= ',';

$in['extended_valid_elements'] .= '@[id|class|style|title|itemscope|itemtype|itemprop|datetime|rel],div,dl,ul,dt,dd,li,span,a|rev|charset|href|lang|tabindex|accesskey|type|name|href|target|title|class|onfocus|onblur]';

return $in;
}
add_filter('tiny_mce_before_init', 'schema_TinyMCE_init' );
</pre>