You need to grab jQuery Here
You need to grab Interface (idrag) Here
And you need to use this little snippit of code for your javascript:
var containerHeight = 0;
var scrollCotent = '';
function getContainerHeight(o) {
containerHeight = $(o).parent().height();
containerHeight -= 20;
}
function getScrollContent(o) {
sc = $(o).next();
sch = sc.height();
}
$(document).ready( function() {
$('.scroll-handle').Draggable(
{
zIndex: 1000,
containment: 'parent',
axis: 'vertically',
opacity: 0.7,
onStart: function() {
getContainerHeight( this );
getScrollContent( this )
},
onDrag : function(x,y)
{
var move = sch - containerHeight;
if(y>0 && y<(containerHeight))
sc.top(- y/containerHeight*move + "px");
return {x: x,y: y}
}
}
);
});