download data in php

$strcnn=mysql_connect("localhost","root","");

mysql_select_db("demodata",$strcnn);



$querry="select * from data where id=1";

$result=mysql_query($querry);

list($id,$filecontent,$filesize,$filename)=mysql_fetch_array($result);

header("Content-Length: $filesize");

header("Content-Type: application/octet-stream");

header("Content-Disposition: attachment; filename=\"$filename\"");

echo $filecontent;



?>