I have two containers. A thumbnail container, and a \"page\" container. Both are divs. Thumbnails can be dragged back and forth between the two containers. I have revert on the
Check the snapping example on the Jquery UI Site:
http://jqueryui.com/demos/draggable/#snap-to
You can take their same example and specify both a grid and a snap parameter.
Then the snap will be based off of the top left corner of the snap selector.
$( "#draggable5" ).draggable({ snap: ".ui-widget-header", grid: [ 80, 80 ] });
The example on the Jquery site will now let the "80x80" box snap based on the big container.
In your situation it might be easiest to create a div with 100% width and height, then set the snap: selector (using css selectors) to that div, then specifying a grid to snap to...
Good Luck