{
    my $validusers = '';
    if ($phpvirtualbox{'adminUser'} || $phpvirtualbox{'userGroups'}) {
	if ($phpvirtualbox{'adminUser'}) {
	    $validusers = "$phpvirtualbox{'adminUser'}";
	    if ($phpvirtualbox{'userGroups'}) {
		$validusers .= ",+$phpvirtualbox{'userGroups'}";
	    }
	} else {
	    if ($phpvirtualbox{'userGroups'}) {
		$validusers = "+$phpvirtualbox{'userGroups'}";
	    }
	}
    }

    $OUT .=<<_VBOX;

[virtualbox]
comment = virtualbox ISO directory
path = /opt/vbox/ISOs
read only = no
writable = yes
printable = no
inherit permissions = yes
create mode = 0640

_VBOX

    if ($validusers) {
	$OUT .= "valid users = $validusers\n";
    }

}