下午好！
我有一个HTML、PHP和MySQL的登录脚本，它运行良好，但当字段为空时，我希望登录页面打印一条带有简单"p"的错误消息。
我的登录php页面：
<form action="includes/loginprocess.php" method="POST">
<input type="text" name="user" placeholder="Username">
<input type="password"name="pass" placeholder="Password">
<input type="submit" value="Login">
</form>
loginprocess.php：
<?php
// Includes the database connection file.
include("mysqlconnection.php");
// Check if there was a POST or if some field are empty.
if (!empty($_POST) AND (empty($_POST['user']) OR empty($_POST['pass']))) {
header("Location: ../login.php"); exit;
}
//And a lot of other things come after...
我想知道的是，是否有任何方法可以让loginprocess.php在login.php中的输入上方回显一些简单的消息，比如：
<form action="loginprocess.php" method="POST">
//This!!!
<p style="color:red;">Fields Empty!</p>
<input type="text" name="user" placeholder="Username">
<input type="password"name="pass" placeholder="Password">
<input type="submit" value="Login">
</form>
这对我帮助很大，谢谢大家。
如果您只想让验证捕捉输入是否为空，那么您应该简单地将输入标记为所需，并让html5验证器为您处理它。
<form action="includes/loginprocess.php" method="POST">
<input type="text" name="user" placeholder="Username" required>
<input type="password"name="pass" placeholder="Password" required>
<input type="submit" value="Login">
</form>