$ret = '';
$arrs = array(array(1,'test1'),
array(2,'test2'),
array(3,'test3'),
array(4,'test4'),
array(5,'test5'),
array(6,'test6'),
array(7,'test7')
);
foreach($arrs as $k=>$arr){
$ret .= $arr[0].",".$arr[1]." \n";
}
//$ret = @mb_convert_encoding ($ret, 'GBK','UTF-8');
header("Content-Disposition: attachment; filename=xxxx.csv");
header("Content-Type:APPLICATION/OCTET-STREAM");
echo $ret;