//JS for the drag-and-drop
function drag(event)
        {
            event.dataTransfer.setData("Text", event.target.id);
        }

function permitDrop(event)
        {
            event.preventDefault();
        }

function drop(event)
        {
            event.preventDefault();
            var data=event.dataTransfer.getData("Text");
            event.target.appendChild(document.getElementById(data));
        }