我正在尝试根据用户是“新”还是“现有”来更改我的登录表单。例如，如果选择“现有用户”仅显示“用户名”和“密码”输入字段。选择“新用户”会得到“用户名”、“电子邮件”、“密码”和“密码确认”。
<select id="login_type" name="logintype">
<option value="Register">a new user</option>
<option value="Login">an existing user</option>
</select>
尝试了下面的代码，但是当它在我的 if else 中读取我的 html 表单时它卡住了。我能做什么？
<?php
if (isset($_POST['login_type']) && $_POST['login_type'] == 'an existing user')
{
<div>
<label for="uname_input">Username:</label>
<input id="uname_input" name="uname" type="text" required="required" placeholder="Enter your username"/>
<br />
<label for="pass_input">Password:</label>
<input id="pass_input" name="passwd" type="password" required="required" placeholder="Enter your password"/>
</div>
<input id="submit_login" type="submit" value="Submit" />
}
else
{
<div class="shownew">
<label for="em_input">Email:</label>
<input id="em_input" name="email" type="text" placeholder="Enter a valid email address"/>
</div>
<div>
<label for="uname_input">Username:</label>
<input id="uname_input" name="uname" type="text" required="required" placeholder="Enter your username"/>
<br />
<label for="pass_input">Password:</label>
<input id="pass_input" name="passwd" type="password" required="required" placeholder="Enter your password"/>
</div>
<div class="shownew">
<label for="pass2_input">Confirm:</label>
<input id="pass2_input" name="passwd2" type="password" placeholder="Repeat your password"/>
</div>
<input id="submit_login" type="submit" value="Submit" />
}
if (isset($_GET['error']))
{
$errmsg = '';
switch ($_GET['error'])
{
case 1: $errmsg = 'Passwords entered do not match one another.'; break;
case 2: $errmsg = 'Username already exists in the database. Please choose a different username.'; break;
case 3: $errmsg = 'The username or password you entered is incorrect. Please try again.'; break;
case 4: $errmsg = 'Invalid login mode. Please reload the page and try again.'; break;
case 5: $errmsg = 'Unexpected error processing login. Please try again'; break;
default: $errmsg = 'An unknown error occurred. Please try again in a few minutes.'; break;
}
print '<p class="errmsg">' . $errmsg . '</p>';
}
?>