i ma getting error while using ckeditor in mvc

Question

i ma getting error while using ckeditor in mvc &nbsp;as&nbsp;<h2 style="font-family: Verdana; font-weight: normal; font-size: 14pt; color: maroon; background-color: #ffffff;"><em>A potentially dangerous Request.Form value was detected from the&nbsp;</em></h2><div>though i am write [allowhtml] in my model class it will not work&nbsp;</div>