login.jsp

<li><input type="text" class="loginuser"
onclick="JavaScript:this.value=''" id="account"
name="account" value="" /></li>
<li><input type="password" class="loginpwd" id="password"
name="password" value="" onclick="JavaScript:this.value=''" />
</li>
<li style="margin-bottom: 15px;"><input name="" type="button"
class="loginbtn" value="登录" onclick="login()" /></li>

function login() {
var errorMsg = "";
var loginName = document.getElementById("account");
var password = document.getElementById("password");
if(!loginName.value){
errorMsg += "&nbsp;&nbsp;用户名不能为空!";
}
if(!password.value){
errorMsg += "&nbsp;&nbsp;密码不能为空!";
}
if(errorMsg != ""){
$(".login_info").html(errorMsg);
$(".login_info").show();
}
else{
$(".login_info").show();
$(".login_info").html("&nbsp;&nbsp;正在登录中...");