php输出excel格式文件

//输出内容如下：
// 输出表头
echo   iconv("utf-8", "gb2312", "客户名称")." ";
echo   iconv("utf-8", "gb2312", "电话")." ";
echo   iconv("utf-8", "gb2312", "地址")." ";
echo   iconv("utf-8", "gb2312", "添加日期")." ";
echo   " ";    //换行

$sqlstr = "select * from clients where usersid=32 order by clientsid desc";
$rows   = $db -> select($sqlstr);
$num    = count($rows); //客户总数
for( $i = 0; $i < $num; $i++ )
{
echo   iconv("utf-8", "gb2312",$rows[$i][clientsname])." ";
echo   iconv("utf-8", "gb2312",$rows[$i][clientsphone])." ";
echo   iconv("utf-8", "gb2312",$rows[$i][clientsaddress])." ";
echo   iconv("utf-8", "gb2312",$rows[$i][clientstime])." ";
echo   " ";    //换行
}
?>

　　header("content-disposition:attachment;filename=users.xls" );

　　echo "公司名称"."t";

　　echo "用户名"."t";

　　echo "密码"."t";

　　echo "二级域名"."t";

　　echo "n";

　　foreach($result['result'] as $val){

　　echo "$val->comname"."t";

　　echo "$val->username"."t";

　　echo "$val->usertruepw"."t";

　　echo emptyempty($val->domainname)?'':('http://'.$val->domainname.'.jiaomai.com')."t";

　　echo "n";

　　}