As you may have noticed, basically there are two kinds of scrollers - the Vertical ones & then there are these horizontal ones. Typically, Vertical ones are used for given out current information which some way relate to the contents of your site. These usually read the contents off external Text files. You update the text file & the scroller message changes automatically. On the other hand, the horizontal ones are generally in-page with short messages.

We usually use Third Party applets that are already available rather than writing them ourselves.