score control (thread 2)

Secondly: the user can move the dot from place to place till he is happy with his choice. Let's say the user places one of the dots to a correct place and gets one point...then changes his mind and places the dot to a wrong place and then gets one point off! But how do I control the score system if the user has placed one of the dots to a correct place, got his one point added to the score and then decides he wants to drag and drop the same dot to another correct place? I do not want the user to get one more point added to his score...each correct place is worth one point but not for the same dot...

Your help will be much appreciated...
Thank you everyone and please heeeeeeeeeeeelp me......