我现在正在编写验证脚本。
<?php
if ($_POST['process'] == 1) {
$first_name = $_POST['first_name'];
$last_name = $_POST['last_name'];
if (empty($first_name) && empty($last_name)){
echo "Howdy, stranger";
}else{
echo "Hello there, ".$first_name." ".$last_name;
}
}
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Form validation example</title>
<style>
input{display:block; margin-bottom:10px;}
</style>
</head>
<body>
<h1>Form Validation Example</h1>
<h2>Please enter your name</h2>
<form action="validation_example.php" method="post">
<label for="first_name">First name:</label>
<input name="first_name" id="first_name" type="text" />
<label for="last_name">Last name:</label>
<input name="last_name" id="last_name" type="text" />
<input type="hidden" name="process" value="1" />
<input type="submit" value="Submit" />
</form>
</body>
</html>
但是，我得到了这个：
Notice: Undefined index: process in on line 2
这是一个相当明显的错误，但我应该投入什么来阻止这行代码运行从而防止错误？