nction (html) { return html.replace(/</g,'&lt;').replace(/\>/g,'&gt;'); }

// frontmatter for simple YAML (support multi-level, but string value only)
md.formatYAML = function (front, matter) {
  var level = {}, latest = md.yaml;
  matter.replace( /^\s*#(.*)$/gm, '' ).replace( /^( *)([^:^\n]+):(.*)$/gm, function(m, sp, key,val) { 
      level[sp] = level[sp] || latest
      latest = level[sp][key.trim()] = val.trim() || {}
      for (e in level) if(e>sp) level[e]=null;
    } );
  return ''
}

//===== format