//ScrollBar
function ScrollBar (target, area) {
//alert("ScrollBar(" + [target, area] + ")");

$('#foot').append($("<span></span>"));

this.target_height = $(target).height();
this.area_height = $(area).height();
this.overflow = this.target_height > this.area_height;

if (this.overflow) {

var p = this;
this.target = target;
this.area = area;
this.scrollbar = "#scrollbar";
this.bar = "#scrollbar .bar";
this.bg = "#scrollbar .bg";
this.target_top_margin = parseInt($(target).css("margin-top"));
this.area_top = $(area).position().top - 9;

$(area).css({"overflow":"hidden"});
$(area).append('<div id="scrollbar"><div class="bar"></div><div class="bg"></div></div>');
$(target).width($(target).width() - $(this.scrollbar).width());

$(target).css({"float":"left", "position":"static"});
$(this.scrollbar).css({"float":"right"});
this.target_height = $(target).height() + this.target_top_margin;

var bar_height = Math.floor(this.area_height / this.target_height * $(this.scrollbar).height());
bar_height = Math.max(bar_height, 10);

$(this.bar).height(bar_height);
$(this.bar).css("top", 0);

$(this.bar).mousedown(function (event) {
p.startDrag(event);
return false;
});

$("body").mouseup(function () {
p.stopDrag();
return false;
});

$(area).wheel(function(event, delta) {
p.scrollTo(p.bar_y - (delta * 8));
if (event.preventDefault) event.preventDefault();
event.returnValue = false;
});

$(this.bg).mousedown(function (event) {
var y = event.pageY - p.area_top > p.bar_y ? bar_height : -bar_height;
p.scrollTo(p.bar_y + y);
return false;
});

this.start_y;
this.max_y = Math.floor($(this.scrollbar).height() - bar_height);
this.min_y = 0;
this.bar_y = 0;
}

return this;
}

ScrollBar.prototype.startDrag = function (event) {
//alert("ScrollBar.startDrag()");

var p = this;
this.start_y = event.pageY - $(p.bar).position().top - p.area_top;

$("body").mousemove(function (event) {
p.scrollTo(event.pageY - p.area_top - p.start_y);
return false;
});
}

ScrollBar.prototype.scrollTo = function (value) {
//alert("ScrollBar.scrollTo(" + value + ")");

this.bar_y = Math.min(Math.max(Math.round(value), this.min_y), this.max_y);
$(this.bar).css("top", this.bar_y);

var target_y = Math.round(this.bar_y / this.max_y * (this.area_height - this.target_height)) + this.target_top_margin;
$(this.target).css("margin-top", target_y);
}

ScrollBar.prototype.stopDrag = function () {
//alert("ScrollBar.stopDrag()");

$("body").unbind("mousemove");
}