...
while (<PLATTS>) {
        if (/^.*?<p>.*?( $sw )/) {  # first if
            ...
            if ( $dec eq "y" ) {    # second if
            ...
            }   # second if CLOSED and DONE WITH

         } else { ## this was intended to work with second if statement, but now works with the first if
           ...
          }
      ...


##</code><code>##

 ...
while (<PLATTS>) {
        if (/^.*?<p>.*?( $sw )/) {  # first if
            ...
            if ( $dec eq "y" ) {    # second if
            ...
            } else { ## NOW else is attached to the second if, and now works as intended
           ...
            }
         } ## END of first if statement.
      ...


##</code><code>##

    open my $fh_output,'>>',$output or die "can't open file: $!";
    open my $fh_input_file1,'<',$input_file1 or die "can't open file: $!";
    open my $fh_input_file2,'<',$input_file2 or die "can't open file: $!";
     ...
            if ( $dec eq "y" ) {
                print "\nadded \n\n";
                ...
                print $fh_output "$sw \t $_ \n";
            }
    ...