How to add a carriage return in the end when using implode?

$subdata has been changed before then $data[$index]=implode(",", $subdata); <<<<<----------what should I change here ? rewrite the file like this : $data[$index]=$data[$index]; $fp=fopen($datafile,"w+"); $a=0; do{ fputs($fp,$data[$a]);<<<<<----------or here?. $a++; }while($a<count($data)); fclose($fp); however if one line of the $datab has been implode with $subdata ,there will not be a 'return' in the final text file , this line just is joined with the next line ,what should I do here to add the $data as a single line? Thanks Leon