SCROLL BOX
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Scroll box ─────┐ ═
│ ┴
Use the scroll box to move quickly to an │ ↑
approximate location in a document. Drag └──►█
the scroll box to the relative position ▒
you want. ▒
For example, to move to the end of a document,
drag the scroll box to the bottom of the scroll
bar. To move to the approximate center of a
document, drag the scroll box halfway down the
scroll bar.