织梦dedecms有现成的二级联动管理，可以添加并生成二级联动的JS代码，使用起来非常方便。如果要实现自己的效果，可能要对联动过程做一点开发。下面的代码实例是在二级联动的过程中，添加了一个新的字段，以保存选项的值，并在前台根据JS的值做不同的事件。
<?phprequire_once(dirname(__FILE__)."/../include/common.inc.php");//查询根节点$dsql->SetQuery("SELECT evalue,ename from `ddmx_sys_enum` where egroup='center' AND evalue%500 = 0 order by disorder asc, evalue asc");$dsql->Execute();
$enums = array();$sort = 1 ;while($row = $dsql->GetArray()){$options .= "<option value="{$sort}">{$row['ename']}</option> ";$enums[] = $row['evalue'];$sort ++ ;}$count = count($enums);foreach($enums as $i=>$evalue){//添加了一个名为link的字段，保存选项的跳转链接。$dsql->SetQuery("SELECT evalue,ename,link from `ddmx_sys_enum` where egroup='center' AND evalue > {$evalue} AND evalue < ({$evalue} + 500) order by disorder asc, evalue asc");$dsql->Execute();$sort = 0 ;$i++;while($row = $dsql->GetArray()){$js .= "select2[". $i ."][{$sort}] = new Option("{$row['ename']}", "{$row['link']}"); ";$sort++;}}$html = '<form name="frm"><div class="city_sch"><h2 class="f13">选择里您最近的学习中</h2><table width="190" height="128" border="0" align="center" cellpadding="0" cellspacing="0"><tr><td height="51" align="center" valign="middle"><label><select name="s1" onChange="redirec(document.frm.s1.options.selectedIndex)"><option selected>点击选择城市</option>'. $options .'</select></label></td></tr><tr>
<td height="22" align="center" valign="middle"><label><select name="s2" id="s2"><option value="点击选择中心" selected>点击选择中心</option></select></label></td></tr><tr><td height="55" align="center" valign="middle"><label><input type="submit" name="button" id="button" value="马上提交"onclick="window.location=document.frm.s2.value;return false;"/></label></td></tr></table></div></form><script language="javascript">var select1_len = document.frm.s1.options.length;var select2 = new Array(select1_len);for (i=0; i<select1_len; i++){select2[i] = new Array();}select2[0][0] = new Option("请选择", " ");'. $js .'function redirec(x){var temp = document.frm.s2;for (i=0;i<select2[x].length;i++){temp.options[i]=new Option(select2[x][i].text,select2[x][i].value);}temp.options[0].selected=true;}</script>';$html = addslashes(str_replace(array(" ", '"'), array('', '''), $html));echo "document.write(" $html ")";?>
