Drag & drop help

1

can anyone help with coding for actionscript 2.0 - we have designed a quiz with drag and drop answer, for each question the user must select the three most appropriate answers and drag them in order into the 3 answer boxes. it is important that the order of importance is recorded. does anyone know how to prevent an answer being dragged to the 2nd or 3rd boxes until the 1st box has been filled, and so on? i hope i’ve made myself clear! if not please ask questions! thanks in advance