>> <cfif FORM["seminars_beginner"& Row] AND FORM["seminars_intermediate"& Row] >
.... This is a shorter way of saying:
<cfif FORM.TheFirstCheckboxValue NEQ 0 AND FORM.TheSecondCheckBoxValue NEQ 0>
It takes advantage of the fact that numbers can be evaluated as boolean. 0 evaluates to FALSE, and other numbers to TRUE.