I've three drop downs as product attribute. Color, Size, and Brand. Now if i select color as pink brand as raymond, size as L and press add button. I am appending one div with the combination of pink, raymond and size L. User can select multiple combinations. My question is how to restrict user to select only unique values. For example if user has selected Pink,Raymond,L and if user is selecting this combination again, at that time an alert should be thrown asking user to select other combination. I've tried to do it like every time when user making selection i am inserting the selected values in hidden field and on add button click i am checking if that value is there in that hidden field or not. It is working for one time but not for multiple time.