TextArea限定输入长度

<script type="text/javascript">

/*

* 限制textarea文本域输入的字符个数

* @id textarea表单ID

* @count 要限制的最大字符数

*/

function limitChars(id, count)

{

var obj = document.getElementById(id);

if (obj.value.length > count)

{

obj.value = obj.value.substr(0, count);

document.getElementById("overCountTips").innerHTML="最多只能输入"+count+"个字符";

}else{

document.getElementById("overCountTips").innerHTML="";

}

}

</script>

<textarea name="description" cols="50" rows="3" id="description" onKeyDown="limitChars('description', 20)" onchange="limitChars('description', 20)" onpropertychange="limitChars('description', 20)"><div class="STYLE4" id="overCountTips" style="display:"></div>