function ValidateLogin() {
alert($("#txtUserName").val());
//alert($('#txtUserName').val());
}<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Login | Profi Admin</title>
<link href="css/960.css" rel="stylesheet" type="text/css" media="all" />
<link href="css/reset.css" rel="stylesheet" type="text/css" media="all" />
<link href="css/text.css" rel="stylesheet" type="text/css" media="all" />
<link href="css/login.css" rel="stylesheet" type="text/css" media="all" />
</head>
<body>
<div class="container_16">
<div class="grid_6 prefix_5 suffix_5">
<h1>Login</h1>
<div id="login">
@*
<p class="tip">You just need to hit the button and you're in!</p>
<p class="error">This is when something is wrong!</p>*@
<form id="form1" name="form1" method="post" action="">
<p>
<label>
<strong>Username</strong>
<input type="text" name="UserName" class="inputText" id="txtUserName" />
</label>
</p>
<p>
<label>
<strong>Password</strong>
<input type="password" name="Password" class="inputText" id="txtPassword" />
</label>
</p>
<a class="black_button" onclick="return ValidateLogin();"><span>Authentification</span></a>
<label>
<input type="checkbox" name="checkbox" id="checkbox" />Remember me</label>
</form>
<br clear="all" />
</div>
<div id="forgot">
<a href="#" class="forgotlink"><span>Forgot your username or password?</span></a>
</div>
</div>
</div>
<br clear="all" />
</body>
</html>在这里，在警报中，我没有得到用户名。我也尝试使用单引号，但仍然没有出现。
最佳答案
也许您忘记了在站点中启用Jquery，因为在下面的示例中它可以完美地工作。
function ValidateLogin() {
alert($("#txtUserName").val());
//alert($('#txtUserName').val());
}<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="container_16">
<div class="grid_6 prefix_5 suffix_5">
<h1>Login</h1>
<div id="login">
<form id="form1" name="form1" method="post" action="">
<p>
<label>
<strong>Username</strong>
<input type="text" name="UserName" class="inputText" id="txtUserName" />
</label>
</p>
<p>
<label>
<strong>Password</strong>
<input type="password" name="Password" class="inputText" id="txtPassword" />
</label>
</p>
<a class="black_button" onclick="return ValidateLogin();"><span>Authentification</span></a>
<label>
<input type="checkbox" name="checkbox" id="checkbox" />
Remember me</label>
</form>
<br clear="all" />
</div>
<div id="forgot">
<a href="#" class="forgotlink"><span>Forgot your username or password?</span></a>
</div>
</div>
</div>
<br clear="all" />