JS控制文本框只能输入N个字符.

1<script type="text/javascript">
2
3function ismaxlength(obj){   
4var mlength=obj.getAttribute? parseInt(obj.getAttribute("maxlength")) : ""   
5if (obj.getAttribute && obj.value.length>mlength)   
6obj.value=obj.value.substring(0,mlength)   
7} 
8
9</script>

1<textarea maxlength="10" onkeyup="return ismaxlength(this)"></textarea>