Customizing scrollbars in flex using css

ScrollBar  {
up-arrow-skin: ClassReference(null);
down-arrow-skin: ClassReference(null);
trackSkin:
Embed(source="/assets/images/scrollbar/scrolltrack.png",
scaleGridLeft="7", scaleGridTop="5",
scaleGridRight="8", scaleGridBottom="7");
thumbDownSkin:
Embed(source="/assets/images/scrollbar/thumb.png",
scaleGridLeft="7", scaleGridTop="5",
scaleGridRight="8", scaleGridBottom="7");
thumbUpSkin:
Embed(source="/assets/images/scrollbar/thumb.png",
scaleGridLeft="7", scaleGridTop="5",
scaleGridRight="8", scaleGridBottom="7");
thumbOverSkin:
Embed(source="/assets/images/scrollbar/thumb.png",
scaleGridLeft="7", scaleGridTop="5",
scaleGridRight="8", scaleGridBottom="7");
}

This css will remove the Up arrow and Down arrows from the ScrollBar.

And the thumb and track of ScrollBar is customized with images(15X15).

By changing the thumb image and track image we change the Scrollars theme