Server.HTMLEncode Method

The HTMLEncode method applies HTML encoding to a specified string. This is useful as a quick method of encoding form data and other client request data before using it in your Web application. Encoding data converts potentially unsafe characters to their HTML-encoded equivalent.

If the string to be encoded is not DBCS, HTMLEncode converts characters as follows:

• The less-than character (<) is converted to <.
• The greater-than character (>) is converted to >.
• The ampersand character (&) is converted to &.
• The double-quote character (") is converted to ".
• Any ASCII code character whose code is greater-than or equal to 0x80 is converted to &#, where is the ASCII character value.

source:http://msdn.microsoft.com/en-us/library/ms525347.aspx