Manual Scroller onMousever not on click

Ive added this just below the body tag;

<a href="javascript:void(0);" onmouseover="movedown()" onmouseout="stopscroll()">Down</a>
<a href="javascript:void(0);" onmouseover="moveup()" onmouseout"stopscroll()">Up</a>

The new 'down' works fine but the new 'up' continues to scroll when you move your mouse off it.

Oops, missed out an '=' sign, seems to be working fine now.

<a href="javascript:void(0);" onmouseover="movedown()" onmouseout="stopscroll()">Down</a>
<a href="javascript:void(0);" onmouseover="moveup()" onmouseout="stopscroll()">Up</a>

Are their likely to be any accessibility or usability issues with this?