If the horizontal scroll bar is visible, and the AllowSizing property of the leftmost split is True, the list displays a split box immediately to the left of the horizontal scroll bar.
To clone the current split, point to the split box. The pointer will change to a double vertical bar with a down arrow.
Drag the pointer to the right to display and move a pair of dividing lines that will mark the right edge of the new split.
The leftmost split box is always used to create a new split. If other split boxes are present, you can use them to reposition the split dividers. Point to the split box you want to move. The pointer will change to a double vertical bar with horizontal arrows.
Drag the dividers left or right to adjust the widths of the adjacent splits. As with columns, you can drag the dividers all the way to the left to hide a split. However, since splits do not have a Visible property, hiding a split in this manner actually deletes it.
If the horizontal scroll bar is not visible, or the AllowSizing property of the leftmost split is False, you can still create a new split with the Split command on the visual editing menu.