How to display an error below a field

In Portal if you omit a required field (as an example) and click Change or Add a red error bubble will display below the required field with an error message indicating it's required.  I'm customizing a form and I'd like to mimic that behavior for a new edit I'm adding.  I couldn't find an example of it in the Design Studio Guide (for Lawson 10).  Does anyone know how to do that?  Thanks, Randy