php 批量添加多行文本框textarea一行一个

$act=!empty($_get['act']) ? trim($_get['act']) : '';
switch($act) {
case 'adda':
$area['a_value'] = trim($_post['a_value']);
$area['a_type']=3;
if(strpos($area['a_value'], "\n") === false) {
//echo $area['a_value'];
//add($area);
//$db->insert('bcrh_article_attr',$area);

}
else
{
$areanames = explode("\n", $area['a_value']);
foreach($areanames as $areaname) {
$areaname = trim($areaname);
if(!$areaname) continue;
//echo $areaname.'|';
$area['a_value'] = $areaname;
//$db->insert('bcrh_article_attr',$area);


}
}
header("refresh:0;url=gfxrtz.php");//跳转页面，注意路径
exit;

break;
}

<form method="post" action="?act=adda" onsubmit="return dcheck();" >
<table cellpadding="2" cellspacing="1" class="tb">
<tr>
<td class="tl"><span class="f_hid">*</span> 属性</td>
<td>

<textarea name="a_value" id="a_value" style="width:200px;height:100px;overflow:visible;"></textarea>
允许批量添加，一行一个，点回车换行</td>
</tr>
</table>
<div class="sbt"><input type="submit" name="submit" value="确 定" class="btn"> <input type="reset" name="reset" value="重 置" class="btn"></div>
</form>