<script type="text/javascript">
function onclickFun() {
var usernameObj = document.getElementById("username");
var usernameText = usernameObj.value;
var patt = /^\w{5,12}$/;正则表达式
var usernameSpanObj = document.getElementById("usernameSpan");
if(patt.test(usernameText)){
usernameSpanObj.innerHTML = "<img src=\"对.png\" width=\"18\" height=\"18\">";
}else {
usernameSpanObj.innerHTML = "<img src=\"错.png\" width=\"18\" height=\"18\">";
}
}
</script>
</head>
<body>
用户名:<input type="text" id="username" value="请输入用户名"/>
<span id="usernameSpan" style="color:red;">
</span>
<button onclick="onclickFun()">校验</button>
正则表达式部分用法