$Pairs{$Person1}   //= $Person1;
      $Pairs{$Person2}   //= $Person2;
      $PairsOf{$Person1} //= "";
      $PairsOf{$Person2} //= "";
      $PairsOf{$Person1}  = $PairsOf{$Person1} . " " . $Person2;
      $PairsOf{$Person2}  = $PairsOf{$Person2} . " " . $Person1;