{ # closure
  my  %HTML_ESCAPE = (
                      "\xa0" => " ",
                      "&" => "&",
                      "'" => "'",
                      "\"" => """,
                      "<" => "&lt;",
                      ">" => "&gt;",
                     );
  
  sub html_escape
  {
    return '' unless defined($_[0]);
    
    (my $t=$_[0]) =~ s/([\xa0\'\"&<>])/$HTML_ESCAPE{$1}/g;
    $t;
  }
}