<!DOCTYPE html>
<html>
<head>
<meta charset="gbk">
<title>用户注册</title>
<script type="text/javascript"src="用户注册.js"></script>
</head>
<body>
<form action="" onsubmit="return check();">
<table>
<tr>
<td>用户名:</td>
<td><input type="text" name="userName" onfocus="showHow();"
onblur="showWrong();" /><span id="userMsg"></span></td>
</tr>
<tr>
<td>密码:</td>
<td><input type="password" name="password" onfocus="showHow2();"
onblur="showWrong2();" /><span id="passMsg"></span></td>
</tr>
<tr>
<td></td>
<td>
<input type="submit" value="确定"/>
</td>
</tr>
</table>
</form>
</body>
</html>
function showHow() {
var msg = document.getElementById("userMsg");
msg.innerHTML = "首位为字母的4-16位数字、字母、下划线";
}
function showWrong() {
var msg = document.getElementById("userMsg");
var name = document.getElementById("form").userName;
if (name.value == "") {
msg.innerHTML = "用户名不能为空";
return false;
}
if (name.value.length < 4) {
msg.innerHTML = "用户名长度须大于4位";
return false;
}
if (name.value.length > 16) {
msg.innerHTML = "用户名长度须在16位以内";
return false;
}
var reg = /^[a-zA-z]{1}\w{3,15}$/;
var result = reg.test(name.value);
if (result == false) {
msg.innerHTML = "输入用户名格式错误";
return false;
}
return true;
}
function showHow2() {
var msg = document.getElementById("passMsg");
msg.innerHTML = "4-10个字母和下划线";
}
function showWrong2() {
var msg = document.getElementById("passMsg");
var word = document.getElementById("form").password;
var reg = /^[a-zA-Z_]{4,10}$/;
if (word.value == "") {
msg.innerHTML = "密码不能为空";
return false;
}
if (word.value.length < 4) {
msg.innerHTML = "密码长度须大于4位";
return false;
}
if (word.value.length > 10) {
msg.innerHTML = "密码长度须在10位以内";
return false;
}
var result = reg.test(word.value);
if (result == false) {
msg.innerHTML = "输入密码格式错误";
return false;
}
return true;
}
function check() {
return showWrong() && showWrong2();
}
function showWrong() {
var msg = document.getElementById("userMsg");
var name = document.getElementById("form").userName;//表单id忘记加了
<form action="" onsubmit="return check();" id="form">