当提交一个HTML表单，它可能需要几秒钟前成功提交，并显示响应页面的形式。人们可以得到空闲，并单击提交按钮几次，这可能会导致重复的表单提交。通常并不真的是一个问题，但在某些情况下，你可能要防止这种情况的发生。
下面你会发现两个简单的技巧，以防止重复提交，您可以使用这些或两者的结合。
»防止多个表单提交使用Javascript
使用Javascript块重复提交可能是最简单的方法。当有人提交表单我们简单地禁用Submit按钮,可能改变它的值为更具描述性的东西,比如“提交,请稍候……”
试着点击这个按钮,例如。它仍将禁用,直到你重新加载此页面:
第一步是要给你的提交按钮一个惟一的id,例如id =“myButton“:
第二个(也是最后一次)的步骤是给两个Javascript命令
/* Set e-mail recipient */
$myemail = "you@domain.com";
/* Check all form inputs using check_input function */
$yourname = check_input($_POST['yourname'], "Enter your name");
$subject = check_input($_POST['subject'], "Write a subject");
$email = check_input($_POST['email']);
$website = check_input($_POST['website']);
$likeit = check_input($_POST['likeit']);
$how_find = check_input($_POST['how']);
$comments = check_input($_POST['comments'], "Write your comments");
//www.software8.co 原文
/* If e-mail is not valid show error message */
if (!preg_match("/([\w\-]+\@[\w\-]+\.[\w\-]+)/", $email))
{
show_error("E-mail address not valid");
}
/* If URL is not valid set $website to empty */
if (!preg_match("/^(https?:\/\/+[\w\-]+\.[\w\-]+)/i", $website))
{
$website = '';
}
/* Let's prepare the message for the e-mail */
$message = "Hello!
Your contact form has been submitted by:
Name: $yourname
E-mail: $email
URL: $website
Like the website? $likeit
How did he/she find it? $how_find
Comments:
$comments
End of message
";
/* Send the message using mail() function */
mail($myemail, $subject, $message);
/* Set a cookie to prevent duplicate submissions */
setcookie('FormSubmitted', '1');
/* Redirect visitor to the thank you page */
header('Location: thanks.htm');
exit();
/* Functions we used */
function check_input($data, $problem='')
{
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
if ($problem && strlen($data) == 0)
{
show_error($problem);
}
return $data;
}
function show_error($myError)
{
?>
Please correct the following error:
exit();
}
?
