Avoid redundancy of HTML entities in .NET framework
Why not just use the Server.HtmlEncode function?  

Here is a brief description of what it does:


  Any ASCII code character whose code is greater-than or equal to 0x80
  is converted to &amp;#&lt;number&gt;, where &lt;number&gt; is the ASCII character
  value.


It also converts common ascii characters such as &lt;, &gt;, &amp;, and " to their html character references.