用于解决问题的例子：
<html>
<head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <title>SetMaxLength</title> <script type="text/javascript" language="javascript"> function fnOnKeyPress() { var obj = window.event.srcElement; if (obj.value.length > obj.maxLength) event.returnValue = false; } function fnOnPaste() { var obj = window.event.srcElement; var maxLen = obj.maxLength; var curLen = obj.value.length; if (curLen >= maxLen) { event.returnValue = false; return; } var newText = window.clipboardData.getData("text"); if (newText.length + curLen <=maxLen ) { event.returnValue = true; return; } event.returnValue = false; if (obj.enableTruncate ) { objobj.value = obj.value + newText.substring(0,maxLen-curLen); } } function fnSetMaxLength(objName, maxLen, enableTruncate) { var obj = document.all(objName); obj.maxLength = maxLen; obj.enableTruncate = enableTruncate; obj.onkeypress = fnOnKeyPress; obj.onpaste = fnOnPaste; } </script>
</head> <body> <textarea id="LongText1"></textarea> <textarea id="LongText2"></textarea> <script type="text/javascript" language="javascript"> fnSetMaxLength("LongText1",50,false); fnSetMaxLength("LongText2",50,true); </script>
</body>
</html>