文本框提示~ 做个备注吧~

<script type="text/javascript">

	<%--提示输入信息--%>
		
	function checkLen(obj) {  

	var maxChars = 200;	<%--最多字符数  --%>
	
	if (obj.value.length > maxChars)  obj.value = obj.value.substring(0,maxChars);  
	
	var curr = maxChars - obj.value.length;  <%--剩餘  --%>
	var currs = maxChars - curr;<%--已有字數  --%>
	document.getElementById("count").innerHTML = curr.toString();
	document.getElementById("counts").innerHTML = currs.toString();
	} 
	</script>

文本
<textarea οnkeyup="checkLen(this)" </textarea>
提示
 <div ><span id="counts">0</span>/<span id="count">200</span></div>