Password issue that contains >,< for a text box shows error

Hi I got below error when password contains special characters >,< etc.
Server Error in '/' Application. A potentially dangerous Request.Form value was detected from the client (frmUserPwd="m$|<i+Ca+"). Description: ASP.NET has detected data in the request that is potentially dangerous because it might include HTML markup or script. The data might represent an attempt to compromise the security of your application, such as a cross-site scripting attack. If this type of input is appropriate in your application, you can include code in a web page to explicitly allow it. For mo ...