by default asp.net checks for the scripts in requests so that if it finds a user that is posting javascript or HTML in a request body it will throw an exception "A potentially dangerous Request.Form value was detected from the client"
but sometimes you need this like when you allow a user to send HTML formatted block like in an article or if you are building a blog engine and u need to enable the user to add affiliation site codes or a google analytics block
in this case all you have to do is to modify your page directive to be
1: <%@ Page Language="c#" AutoEventWireup="false" ValidateRequest="false" %>
ValidateRequest attribute makes sure that asp.net disables this validation
you can also add this node to the page section in web.config
1: <pages validateRequest="false" />
but of course this is not recommended as it would disable all validation on all pages.
when using these changes please do not forget to make your own validation
