sub duplicate_record {
   
   my $html_title = 'Duplicate records have been found!';
   die("Cannot open file for matching\n") unless open (DBFILE, "dbfile.pdb");
   while (<DBFILE> and $found == 0) { #while not eof file and pattern not matched ($found == 0)
      foreach $record (<DBFILE>) { #foreach line ($record)
         @pattern_check = split(/,/, $record); #spit line where you see comma (,) ($record)
         if ($name eq $pattern_check[0] and $surename eq $pattern_check[1]) { #check if duplicate is available
            print $cgi-> start_html("$html_title").
               $cgi-> h1('Duplicate records:').
               $cgi-> p("$name $surename $phone already exists.\nGo back and fill something else than that!").
               $cgi-> end_html;
               $found = 1;
         }#if
      }#foreach
   }#while
   
   close (DBFILE);

   if ($found == 0) {
      save_db();
   }#if 
}# sub duplicate_record