Drag & drop split layout, same text?

Hi,

When I open a text in both panes (same ‘document’ in each pane), I can drag and drop a selection from the right to the left pane for example. But the dragged text on the right is not removed, so I actually copy text instead.

Is there a pref or key combination to prevent this? I thouroughly searched the forum and FAQ’s but did not find an answer.

Thanks,
Max