Drag And Snap

I was wondering how I could make a line of movie clips, say 5 or 6, and allow them all to be dragged and snapped to the closest coordinate. Say, for instance, like a picture gallery. There are 5 pictures in a horizontal line. If you click on one of them and, while still keeping the mouse button down, move the mouse from side to side, all the pictures will move with the one you clicked. When you release the mouse button, all the pictures will fall into a proper place. Say that each picture is 16x16. There are 10 16x16 tiles where the pictures will fit into perfectly. If you release the mouse button when all the pictures are above a 16x16 tile, they stay where they are. But if you release the mouse button when the pictures are in between two of the tiles, they will snap into the closest tile.

I hope I explained it well enough. Any help will be greatly appreciated. Thanks in advance.