Access File Locking

I am running IIS on a win2000 machine linking to an MDB file with php. If the MDB is opened in access the website will display this error when attempting to view the web page:

Warning: SQL error: [Microsoft][ODBC Microsoft Access Driver] Could not use '(unknown)'; file already in use., SQL state S1000 in SQLConnect in c:\inetpub\wwwroot\php\agencydb\extlist.php on line 18
Could Not Make Connection

Otherwise the data will display here is the code:

echo "<P>New Area<P>";
$odbc_dsn = "agencydb";
$odbc_userid = " ";
$odbc_password = " ";
$query = "SELECT * FROM webidquery;";

if(!($odbc_db = odbc_connect($odbc_dsn, $odbc_userid, $odbc_password)))
die("Could Not Make Connection");

if(!($odbc_rs = odbc_do($odbc_db, $query)))
die("Could not work query");

$num_cols = odbc_num_fields($odbc_rs);
if($num_cols < 1) die("No Values");

echo " ", odbc_result($odbc_rs, 1);

Why is this please and how does one fix it please? Looked around for documentation but can not find it.
Thanks in advance