Fix it please.

Server Error in '/' Application. A potentially dangerous Request.Form value was detected from the client (EDU_1_notes="...sed air:
 Converted 4..."). Description: Request Validation has detected a potentially dangerous client input value, and processing of the request has been aborted. This value may indicate an attempt to compromise the security of your application, such as a cross-site scripting attack. You can disable request validation by setting validateRequest=false in the Page directive or in the configuration section. However, it is strongly recommended that your application explicitly check all inputs i ...