Save html from web page to database

I got this text box on one of my admin pages. Employees enter text in here, save it and it's displayed on the web page.
Now I teached them basic html (bold, undeline, paragraphs), so they can format their text.
But after they try to save text containing html, the page throw out an error saying:

Code:

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A potentially dangerous Request.Form value was detected from the client (overview_en="<b>A QUALITY LEADER<...").
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 in this case.

Exception Details: System.Web.HttpRequestValidationException: A potentially dangerous Request.Form value was detected from the client (overview_en="<b>A QUALITY LEADER<...").

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uuuh...ok...whatever