public string Texttohtml(string chr)
  {
  
   if(chr==null)
    return "";
   chr=chr.Replace("<","&lt");
   chr=chr.Replace(">","&gt");
   chr=chr.Replace("\n","<br/>");
   chr = Regex.Replace(chr,@"\[url=(?<x>[^\]]*)\](?<y>[^\]]*)\[/url\]",@"<a href=$1 target=_blank>$2</a>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[url\](?<x>[^\]]*)\[/url\]",@"<a href=$1 target=_blank>$1</a>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[email=(?<x>[^\]]*)\](?<y>[^\]]*)\[/email\]",@"<a href=$1>$2</a>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[email\](?<x>[^\]]*)\[/email\]",@"<a href=$1>$1</a>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[flash](?<x>[^\]]*)\[/flash]",@"<OBJECT codeBase=http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=4,0,2,0 classid=clsid:D27CDB6E-AE6D-11cf-96B8-444553540000 width=500 height=400><PARAM NAME=movie VALUE=""$1""><PARAM NAME=quality VALUE=high><embed src=""$1"" quality=high pluginspage='http://www.macromedia.com/shockwave/download/index.cgi?P1_Prod_Version=ShockwaveFlash' type='application/x-shockwave-flash' width=500 height=400>$1</embed></OBJECT>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[img](?<x>[^\]]*)\[/img]",@"<IMG SRC=""$1"" border=0>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[color=(?<x>[^\]]*)\](?<y>[^\]]*)\[/color\]",@"<font color=$1>$2</font>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[face=(?<x>[^\]]*)\](?<y>[^\]]*)\[/face\]",@"<font face=$1>$2</font>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[size=1\](?<x>[^\]]*)\[/size\]",@"<font size=1>$1</font>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[size=2\](?<x>[^\]]*)\[/size\]",@"<font size=2>$1</font>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[size=3\](?<x>[^\]]*)\[/size\]",@"<font size=3>$1</font>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[size=4\](?<x>[^\]]*)\[/size\]",@"<font size=4>$1</font>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[align=(?<x>[^\]]*)\](?<y>[^\]]*)\[/align\]",@"<align=$1>$2</align>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[fly](?<x>[^\]]*)\[/fly]",@"<marquee width=90% behavior=alternate scrollamount=3>$1</marquee>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[move](?<x>[^\]]*)\[/move]",@"<marquee scrollamount=3>$1</marquee>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[glow=(?<x>[^\]]*),(?<y>[^\]]*),(?<z>[^\]]*)\](?<w>[^\]]*)\[/glow\]",@"<table width=$1 style='filter:glow(color=$2, strength=$3)'>$4</table>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[shadow=(?<x>[^\]]*),(?<y>[^\]]*),(?<z>[^\]]*)\](?<w>[^\]]*)\[/shadow\]",@"<table width=$1 style='filter:shadow(color=$2, strength=$3)'>$4</table>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[b\](?<x>[^\]]*)\[/b\]",@"<b>$1</b>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[i\](?<x>[^\]]*)\[/i\]",@"<i>$1</i>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[u\](?<x>[^\]]*)\[/u\]",@"<u>$1</u>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[code\](?<x>[^\]]*)\[/code\]",@"<pre id=code><font size=1 face='Verdana, Arial' id=code>$1</font id=code></pre id=code>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[list\](?<x>[^\]]*)\[/list\]",@"<ul>$1</ul>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[list=1\](?<x>[^\]]*)\[/list\]",@"<ol type=1>$1</ol id=1>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[list=a\](?<x>[^\]]*)\[/list\]",@"<ol type=a>$1</ol id=a>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[\*\](?<x>[^\]]*)\[/\*\]",@"<li>$1</li>",RegexOptions.IgnoreCase);
   chr = Regex.Replace(chr,@"\[quote](?<x>.*)\[/quote]",@"<center>—— 以下是引用 ——<table border='1' width='80%' cellpadding='10' cellspacing='0' ><tr><td>$1</td></tr></table></center>",RegexOptions.IgnoreCase);
   return(chr); 
  }
  public string htmltoText(string chr)
  {
   if(chr==null)
    return "";
   chr=chr.Replace("'","''");
   return(chr); 
  }