html转换成ubb 函数

function pattern(str){
   //str = str.replace(/(rn|n|r)/ig, '');
   str = str.replace(/<br[^>]*>/ig,'n');
   str = str.replace(/<p[^>/]*/>/ig,'n');
   //str = str.replace(/[code](.+?)[/code]/ig, function($1, $2) {return phpcode($2);}); 
   str = str.replace(/son[w]{3,16}s?=s*(['"]).+?1/ig,'');

   str = str.replace(/<hr[^>]*>/ig,'[hr]');
   str = str.replace(/<(sub|sup|u|strike|b|i|pre)>/ig,'[$1]');
   str = str.replace(/</(sub|sup|u|strike|b|i|pre)>/ig,'[/$1]');
   str = str.replace(/<(/)?strong>/ig,'[$1b]');
   str = str.replace(/<(/)?em>/ig,'[$1i]');
   str = str.replace(/<(/)?blockquote([^>]*)>/ig,'[$1blockquote]');

   str = str.replace(/<img[^>]*smile="(d+)"[^>]*>/ig,'[s:$1]');
   str = str.replace(/<img[^>]*src=['"s]*([^s'"]+)[^>]*>/ig,'[img]'+'$1'+'[/img]');
   str = str.replace(/<a[^>]*href=['"s]*([^s'"]*)[^>]*>(.+?)</a>/ig,'[url=$1]'+'$2'+'[/url]');
   //str = str.replace(/<h([1-6]+)([^>]*)>(.*?)</h1>/ig,function($1,$2,$3,$4){return h($3,$4,$2);});

   str = str.replace(/<[^>]*?>/ig, '');
   str = str.replace(/&amp;/ig, '&');
   str = str.replace(/&lt;/ig, '<');
   str = str.replace(/&gt;/ig, '>');

   return str;
  }
 function htmltoubb(){
  str = pattern(document.getElementById("htmlsource").value);
  document.getElementById("ubbresult").value=str;
 }