Can't make VM 2 show user error messages

[MAtkins]

I searched and can't find anything on this.

If a user forgets to do something like check the 'terms' checkbox, the cart page just refreshes and does not notify the user as to why it didn't go through.
How can I make it tell the user what they did wrong?

[jenkinhill]

Include <jdoc:include type="message" /> in your Joomla template header to allow Joomla to report front end errors

[MAtkins]

Well, that helps, sort of.
Is there any way to get a formatted ERROR within the page instead of just text above the header?

I don't want to display messages like 'Product Successfully Added'
I just want errors like 'Email address was not valid', and it'd be nice if it was properly formatted within the shopping cart part of the page.