SDBM_File Error: Argument "O_RDWR" isn't numeric in null operation

I am writing a script which accesses a DBM file using SDBM. The
program works but throws out a warning of: -

Argument "O_RDWR" isn't numeric in null operation

I've included Fcntl but that doesn't solve the problem. Does anyone
why this is happening?


Thanks
Richard


use SDBM_File;
use Fcntl;

tie (%DB, 'SDBM_File', "fund.dbm",O_RDWR, 0644) or die "Couldn't find
file\n";

foreach $fund (keys %DB) {
print $fund;
}

untie %DB;