JavaScript动态显示可输入的字数提示还可以输入的字数
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>限制文件字数字</title>
<script type="text/javascript">
function setShowLength(obj, maxlength, id)
{
var rem = maxlength - obj.value.length;
var wid = id;
if (rem < 0){
rem = 0;
}
document.getElementById(wid).innerHTML = "还可以输入" + rem + "字数";
}
</script>
</head>
<body>
<input name="title" type="text" size="50" value="" maxlength="15" onkeyup="javascript:setShowLength(this, 15, 'cost_tpl_title_length');"><span class="red" id="cost_tpl_title_length">还可以输入15字数</span>
</body>
</html>
