sub validate_text
  {
  my $wstring = $ts_box->get("1.0", "end") =~ s/\s+/ /gr;
  $ts_box->delete('1.0', 'end');
  $ts_box->insert('end', $wstring);
  $ts_box->tagAdd( 'badc', "1.$-[0]", "1.$+[0]" )
    while $wstring =~ /[^A-Za-z0-9 \/.,=?*+]+/g;
  }