if ( $dr4 < 0 ) {

                #pre-populate deletion array;
                my @delarray = ( 0 .. $chntot + 1 );
                @dlarray = shuffle @delarray;

                my $cndiea = 0;
                foreach my $del ( 0 .. $chntot ) {
                    if ( $aod[$del][$yb] eq 'd' ) {
                        $cndiea++;
                    }
                }
                my $cnr = 0;
                my $cnx = $cndiea;
                while (  $cnx < $incrsdel ) {
                    foreach my $xd ( 0 .. $chntot) {
                        my $xda = $dlarray[$xd];
                        if ( $aod[$xda][$yb] eq 'a' ) {
                            $aod[$xda][$yb] = 'd';
                            $cnr++;
                        }
                    }
                    $cnx = $cnr;
                }


##</code><code>##

            
            if ( $dr4 < 0 ) {
                #pre-populate deletion array;
            	my @delarray = ( 0 .. $chntot + 1 );
            	@dlarray = shuffle @delarray;

                my $cndiea = 0;
                foreach my $del ( 0 .. $chntot ) {
                    if ( $aod[$del][$yb] eq 'd' ) {
                        $cndiea++;
                    }
                }
                my $cnr = $cndiea;
                foreach my $xd ( $cnr .. $incrsdel - 1 ) {
                    my $xda = $dlarray[$xd];
                    if ( $aod[$xda][$yb] eq 'a' ) {
                        $aod[$xda][$yb] = 'd';
                    }
                }
            }