// must exist: dtd
//<!ELEMENT test_variable (variable_test | and_test | or_test |
// not_test)>
Element el_varandornot = (Element) el_testvar.selectSingleNode("variable_test|and_test|or_test|not_test");
String elname = el_varandornot.getName();
ScoreBooleanEvaluable sbe = QTIHelper.getSectionBooleanEvaluableInstance(elname);
float totalscore = getScore();
boolean fulfilled = sbe.eval(el_varandornot, totalscore);
if (fulfilled) {
// get feedback
Element el_displayfeedback = (Element) el_oft.selectSingleNode("displayfeedback");
String linkRefId = el_displayfeedback.attributeValue("linkrefid");
// must exist (dtd)