Controls how the text scrolls in the marquee.
Default value
Blank – equivalent to Scroll.
Valid values
Blank or 'alternate', 'scroll' or 'slide'
'Scroll' - The banner content scrolls in the direction specified by the scroll_direction property. The text scrolls off the end of the banner and starts over.
'Slide' - The banner content scrolls in the direction specified by the scroll_direction property. The text scrolls to the end of the banner and stops. Note that, in Firefox, the animation does not stop. The text will scroll off the end of the banner and start over, making 'slide' effectively the same as 'scroll'.
'Alternate' - The scroll_direction reverses when the content reaches the edge of the banner.
