let header ?(title="") ?(comment="") ?stylesheet_link () =
  let package_str =
    match stylesheet_link with
    | None -> ""
    | Some f -> ~% "\\usepackage{%s}" f
  in
  ~% "\\documentclass[a4paper,10pt]{article}\n\n\\clubpenalty=10000\n\\widowpenalty=10000\n\n\\usepackage[T1]{fontenc}\n\\usepackage[english]{babel}\n\\usepackage{multirow}\n\\usepackage{tipa}\n\\usepackage{ucs}\n\\usepackage[utf8x,utf8]{inputenc}\n\\usepackage[                         \nbookmarks         = true,         \nbookmarksnumbered = true,         \ncolorlinks        = true,         \n]{hyperref}                           \n\\usepackage{color}\n\\definecolor{webred}{rgb}{0.3,0,0}\n\\definecolor{blurl}{rgb}{0,0,0.3}\n\\hypersetup{\nlinkcolor         = webred, %%black\ncitecolor         = webred, %%black\nurlcolor          = blurl , %%black\nlinkbordercolor   = {1 1 1},\ncitebordercolor   = {1 1 1},\nurlbordercolor    = {1 1 1},\npdfauthor   = {},\npdftitle    = {%s},\npdfsubject  = {},\npdfkeywords = {},\npdfcreator  = {Bracetax and PDFLaTeX},\npdfproducer = {Bracetax and PDFLaTeX}}\n\n\\usepackage[pdftex]{graphicx}\n\\frenchspacing\n\\DeclareGraphicsExtensions{.jpg,.mps,.pdf,.png}\n\n%%%s\n%s\n\n\\begin{document}\n\n" title (sanitize_comments comment) package_str