Flash :: Using A Dictionary Variable To Match Up A Drop And Drag Exercice?

I am using a dictionary variable to match up a drop and drag exercice.

var dict = new Dictionary ();
dict[box_a]=s1;
dict[box_b]=s2;
dict[box_c]=s3;
dict[box_d]=s4;

question 1: at the end i would like to check if box_a== with s1 and so on .... how would I do that

for each( var item in dict)
{ item.removeEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler);
item.removeEventListener(MouseEvent.MOUSE_UP, mouseUpHandler);[code]....

question 2:I would like box_d to accept also s3 how would i do that if i do

dict[box_d]=s4; and dict[box_d]=s3; it wont work because it matches it with the last equal.