still haven got update of final for the opera 10?

i got one question here. why once in a while, there is a black line in the middle of my browser? what is the use of that?

The new Opera Scroll Marker makes it easier to continue reading when you scroll through a Web page. At the end of the page it will indicate the previous position of the bottom of the screen so you can easily see where to continue reading.

Enable Opera Scroll Marker in the Preferences dialog box. Navigate to Tools > Preferences > Advanced > Browsing > Show scroll marker (check box).

- Check the box to enable Opera Scroll Marker
- Leave the box unchecked (default) to keep it disabled

Using the opera:config Preferences Editor opera:config#UserPrefs|EnableScrollMarker, you can also set Opera Scroll Marker to show every time you scroll less than a full page down or up. The options in the drop-down menu are:

0 — off
1 — show when reaching the bottom or top of the page
2 — always show when scrolling