php connect access database

$conn = new com("ADODB.Connection");
$connstr = "DRIVER={Microsoft Access Driver (*.mdb)}; DBQ= ". realpath("data/db.mdb");

$conn->Open($connstr);
$rs = new com("ADODB.RecordSet");
$rs->Open("select * from szd_t",$conn,1,1);
while(! $rs->eof)
$f = $rs->Fields(1);
echo $f->value;
$rs ->MoveNext();
?>