查找了很多方法，有些不能实现（被滚动内容的宽度未知，但使用这种方法必须已知），其它的不能完全兼容这些浏览器（IE6，Firefox，Chrome）。最后决定使用JQuery的Slider控件。
1. 下载jquery-1.3.2.min.js，jquery-ui-1.7.1.custom.min.js
2. Html
<div id="topslider" runat="server"></div>
<div id="scroll" runat="server">
<div id="holder">
滚动内容
</div>
<div id="bottomslider" style="margin-top:10px;margin-bottom:10px;" runat="server"></div>
3. css
<style>
#topslider {
width: 98%;
height: 6px;
background: #BBBBBB;
position: relative;
}
#bottomslider {
width: 98%;
height: 6px;
background: #BBBBBB;
position: relative;
}
.ui-slider-handle {
width: 8px;
height: 14px;
position: absolute;
top: -4px;
background: #478AFF;
border: solid 1px black;
}
#scroll {
width: 100%;
margin-top: 10px;
overflow: hidden;
}
#holder {
width: 100%;
}
</style>
4. js
<script type="text/javascript" src="JavaScript/jquery-1.3.2.min.js"></script>
<script type="text/javascript" src="JavaScript/jquery-ui-1.7.1.custom.min.js"></script>
$(document).ready(function(){
$("#topslider").slider({
animate: true,
change: handleSliderChange,
slide: handleSliderSlide,
stop:handleTopSliderStop
});
$("#bottomslider").slider({
animate: true,
change: handleSliderChange,
slide: handleSliderSlide,
stop:handleBottomSliderStop
});
});
function handleSliderChange(e, ui)
{
var maxScroll = $("#scroll").attr("scrollWidth") - $("#scroll").width();
$("#scroll").animate({scrollLeft: ui.value * (maxScroll / 100) }, 1000);
}
function handleSliderSlide(e, ui)
{
var maxScroll = $("#scroll").attr("scrollWidth") - $("#scroll").width();
$("#scroll").attr({scrollLeft: ui.value * (maxScroll / 100) });
}
function handleTopSliderStop(e, ui)
{
$("#bottomslider").slider('value',$("#topslider").slider('value'));
}
function handleBottomSliderStop(e, ui)
{
$("#topslider").slider('value',$("#bottomslider").slider('value'));
}