sub db_update_field {
    my $table = shift;
    my $record = shift;
    my $field = shift;
    my $value = shift;    

    my $dbh = dbconnect();
    my $db_update_field = $dbh->prepare (
       "UPDATE $table SET $field = ? WHERE id = ?"
    );
    $db_update_field->execute ($value, $record);
}