Images in background aren't draggable

Images in background aren't draggable

Hi there,

I'm new to this forum and to jQuery so I don't quite know the etiquette on how exactly to ask my question, but here's what's going on. I'm hoping to make a site with a collage of draggable images (sliced up in photoshop) with many layers. I want people to be able to drag away pieces of a top layer to get to the images underneath, and then be able to drag those away to more images underneath, and so on. 

The issue is, whenever an image is placed behind another in the browser, it suddenly isn't draggable. If I flip the top images to the background and vice versa, without changing any of the draggable functions, the draggability flips and again only the images on top can be dragged. 

I can attach the code somehow but I don't know what's customary. I could of course copy and paste it into a reply if anyone's curious to look at it directly. 

thanks in advance for the help.