获取当前栏目ID
<?php $a = $GLOBALS['navclassid']; ?>获取当前栏目的上级栏目ID
<?php $a = $GLOBALS['navclassid']; $b = $class_r[$a]['bclassid']; ?>获取上上级栏目ID和顶级栏目ID
<?php $aa = $GLOBALS['navclassid']; $bb = $class_r[$aa]['bclassid']; $cc = $class_r[$bb]['bclassid']; $dd = $class_r[$cc]['bclassid']; ?>
