Page Comparison

...

The ondrop event activates when the mouse is released during a drag and drop operation and the element is dropped.  If the Drag and Drop Response screen-level properties are defined, the screen will be submitted automatically.  The operation can be canceled cancelled using the pui.dragDropInfo.cancel flag.  Information about the drag and drop operation is provided using the global pui.dragDropInfo object, which will contain the following properties:

...

if (pui.dragDropInfo\["target element id"\] == "Trash") {
  changeElementValue("DeletedItems", Number(get("DeletedItems")) + 1);
}

Ask the user to confirm the drag and drop operation:

if (\!confirm("Are you sure?")) {
  pui.dragDropInfo.cancel = true;
}