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<html>
<head>
<title>测试专用页
</title>
</head>
<body>
<form method=post name=ceshi action="index.htm">
<textarea name=textarea1 onpropertychange=checkMaxLen(this,20,0)></textarea>
</form>
</body>
<html>
<script language=javascript>
var oldValue=new Array();
function checkMaxLen(obj,maxlength,num){
if(obj.value.length>maxlength){
obj.value=oldValue[num];
}
else{
oldValue[num]=obj.value;
}
}
</script>
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