PHP开发之表单验证邮件和URL

$name = test_input($_POST["name"]);
if (!preg_match("/^[a-zA-Z ]*$/",$name))
  {
  $nameErr = "只允许字母及空格"; 
  }

$email = test_input($_POST["email"]);
if (!preg_match("/([\w\-]+\@[\w\-]+\.[\w\-]+)/",$email))
  {
  $emailErr = "非法邮件地址"; 
  }

$website = test_input($_POST["website"]);
if (!preg_match("/\b(?:(?:https?|ftp):\/\/|www\.)[-a-z0-9+&@#\/%?=~_|!:,.;]*[-a-z0-9+&@#\/%=~_|]/i",$website))
  {
  $websiteErr = "不合法的 URL"; 
  }

<?php
// 定义变量并设为空值
$nameErr = $emailErr = $genderErr = $websiteErr = "";
$name = $email = $gender = $comment = $website = "";
if ($_SERVER["REQUEST_METHOD"] == "POST")
{
  if (empty($_POST["name"]))
    {$nameErr = "Name is required";}
  else
    {
    $name = test_input($_POST["name"]);
    // check if name only contains letters and whitespace
    if (!preg_match("/^[a-zA-Z ]*$/",$name))
      {
      $nameErr = "Only letters and white space allowed"; 
      }
    }
  if (empty($_POST["email"]))
    {$emailErr = "Email is required";}
  else
    {
    $email = test_input($_POST["email"]);
    // check if e-mail address syntax is valid
    if (!preg_match("/([\w\-]+\@[\w\-]+\.[\w\-]+)/",$email))
      {
      $emailErr = "Invalid email format"; 
      }
    }
  if (empty($_POST["website"]))
    {$website = "";}
  else
    {
    $website = test_input($_POST["website"]);
    // check if URL address syntax is valid (this regular expression also allows dashes in the URL)
    if (!preg_match("/\b(?:(?:https?|ftp):\/\/|www\.)[-a-z0-9+&@#\/%?=~_|!:,.;]*[-a-z0-9+&@#\/%=~_|]/i",$website))
      {
      $websiteErr = "Invalid URL"; 
      }
    }
  if (empty($_POST["comment"]))
    {$comment = "";}
  else
    {$comment = test_input($_POST["comment"]);}
  if (empty($_POST["gender"]))
    {$genderErr = "Gender is required";}
  else
    {$gender = test_input($_POST["gender"]);}
}
?>