Simplify the following text for a Grade 8 native English-speaking person.
Original: It was supposed to modify the behavior of the arrow keys and when the scroll lock mode was turned on , the arrow keys would scroll the contents of a text window instead of moving the cursor .
Simplified: In the original design , Scroll Lock was intended to modify the behavior of the arrow keys . When the Scroll Lock mode was on , the arrow keys would scroll the contents of a text window instead of moving the cursor .