<div id="theDiv" style="border:1px solid green;width:100px;height:120px;overflow:hidden">
<div id="content">
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</div>
</div>
<br>
<button id="downButton" onclick="downIt()" >向下</button>
<button id="upButton" onclick="upIt()" disabled=true>向上</button>
<script language="javascript">
function downIt(){
theDiv.doScroll("pageDown");
resetButton();
}
function upIt(){
theDiv.doScroll("pageUp");
resetButton();
}
function resetButton(){
upButton.disabled = false;
downButton.disabled = false;
if(theDiv.scrollTop == 0){
upButton.disabled = true;
}
if(theDiv.scrollTop == content.offsetHeight - theDiv.clientHeight){
downButton.disabled = true;
}
}
</script>
<div id="content">
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</div>
</div>
<br>
<button id="downButton" onclick="downIt()" >向下</button>
<button id="upButton" onclick="upIt()" disabled=true>向上</button>
<script language="javascript">
function downIt(){
theDiv.doScroll("pageDown");
resetButton();
}
function upIt(){
theDiv.doScroll("pageUp");
resetButton();
}
function resetButton(){
upButton.disabled = false;
downButton.disabled = false;
if(theDiv.scrollTop == 0){
upButton.disabled = true;
}
if(theDiv.scrollTop == content.offsetHeight - theDiv.clientHeight){
downButton.disabled = true;
}
}
</script>