I have implemented this and it is supported in major browsers. Hope it helps!
Moving the error messages
Depending on how you set up your form, the error messages that appear on each field may be in the wrong position. Use this CSS to move the error messages below the field. You may need to tweak the left or top amounts until it appears correct on your form.
<style type="text/css">
span.mktFormMsg
{
left: 0px !important;
top: 15px !important;
}
</style>
Source: https://community.marketo.com/MarketoArticle?id=kA050000000Kyss