en.javascript.info/2-ui/3-event-details/8-onscroll/2-updown-button/task.md
Ilya Kantor 8360ebbe90 up
2017-03-12 12:54:13 +03:00

16 lines
501 B
Markdown

importance: 5
---
# Up/down button
Create a "to the top" button to help with page scrolling.
It should work like this:
- While the page is not scrolled down at least for the window height -- it's invisible.
- When the page is scrolled down more than the window height -- there appears an "upwards" arrow in the left-top corner. If the page is scrolled back, it disappears.
- When the arrow is clicked, the page scrolls to the top.
Like this:
[iframe border="1" height="200" link src="solution"]