Drag and drop problem

Hi all. I am trying to do this. I split a phrase to letters and i make them movieclips.Then i want to drag those letters to their corresponding boxes and with hitTest to drop it in. I manage to drag the but the problem is that only the last box works with hitTest. I dont know if i explain it correctly cause english is not my mother language but here is the .fla http://christomanos.com/flash/lettergame.fla

Thanks in advance!