使用php和jQuery验证captcha和联系人表单

我是jQuery的新手。

我有一个带有captcha验证的html联系表格。

该表单使用jQuery来验证名称、电子邮件地址和消息。

但我在整合captch验证时遇到了问题。

（由verifyimage.php）使用以下代码生成captcha：

<?php
session_start();
error_reporting( 0 );
if( !function_exists( "imagecreatefrompng" ) )
{
    exit( "You need to recompile with the GD library included in PHP for this feature to be able to function" );
}
$alphanum = "ABCDEFGHIJKLMNPQRSTUVWXYZ123456789";
$rand = substr( str_shuffle( $alphanum ), 0, 6 );
$image = imagecreatefrompng( "../images/verify.png" );
$textColor = imagecolorallocate( $image, 150, 150, 150 );
imagestring( $image, 5, 14, 22, $rand, $textColor );
$_SESSION['image_random_value'] = md5( $rand );
header( "Expires: Mon, 26 Jul 1997 05:00:00 GMT" );
header( "Last-Modified: ".gmdate( "D, d M Y H:i:s" )." GMT" );
header( "Cache-Control: no-store, no-cache, must-revalidate" );
header( "Cache-Control: post-check=0, pre-check=0", false );
header( "Pragma: no-cache" );
header( "Content-type: image/png" );
imagepng( $image );
imagedestroy( $image );
?>

表单的HTML如下：

<!-- Contact Form -->
<div id="contactForm">
        <form action="/contact.php" method="post">
        <div class="oneThird">
            <div class="row">
                <label for="contactName">Full Name</label>
                <input id="contactName" name="contactName" type="text" />
            </div>
            <div class="row topMargin">
                <label for="contactEmail">Email Address</label>
                <input id="contactEmail" name="contactEmail" type="text" />
            </div>
                        <div class="row topMargin">
                <label for="contactVerify">Captcha</label>
                <input style="background-image: url(/php/verifyimage.php);" id="contactVerify" name="contactVerify" type="text" />
            </div>
                    </div>
        <div class="twoThird lastColumn">
            <div class="row">
                <label for="contactMessage">Message</label>
                <textarea id="contactMessage" name="contactMessage" cols="10" rows="9"></textarea>
            </div>
        </div>
        <div class="clearfix">
        </div>
        <button type="submit" class="colorButton">Send Message</button>
    </form>
    </div>

jQuery包括以下与验证表单名称、电子邮件和消息部分相关的代码：

// Contact
    if ($('#contactForm').length != 0)
    {
        var labelName = $('#contactForm label[for="contactName"]').text();
        var labelEmail = $('#contactForm label[for="contactEmail"]').text();
        var labelMessage = $('#contactForm label[for="contactMessage"]').text();
        var emailPattern = new RegExp(/^((([a-z]|'d|[!#'$%&''*'+'-'/='?'^_`{'|}~]|['u00A0-'uD7FF'uF900-'uFDCF'uFDF0-'uFFEF])+('.([a-z]|'d|[!#'$%&''*'+'-'/='?'^_`{'|}~]|['u00A0-'uD7FF'uF900-'uFDCF'uFDF0-'uFFEF])+)*)|(('x22)(((('x20|'x09)*('x0d'x0a))?('x20|'x09)+)?((['x01-'x08'x0b'x0c'x0e-'x1f'x7f]|'x21|['x23-'x5b]|['x5d-'x7e]|['u00A0-'uD7FF'uF900-'uFDCF'uFDF0-'uFFEF])|(''(['x01-'x09'x0b'x0c'x0d-'x7f]|['u00A0-'uD7FF'uF900-'uFDCF'uFDF0-'uFFEF]))))*((('x20|'x09)*('x0d'x0a))?('x20|'x09)+)?('x22)))@((([a-z]|'d|['u00A0-'uD7FF'uF900-'uFDCF'uFDF0-'uFFEF])|(([a-z]|'d|['u00A0-'uD7FF'uF900-'uFDCF'uFDF0-'uFFEF])([a-z]|'d|-|'.|_|~|['u00A0-'uD7FF'uF900-'uFDCF'uFDF0-'uFFEF])*([a-z]|'d|['u00A0-'uD7FF'uF900-'uFDCF'uFDF0-'uFFEF])))'.)+(([a-z]|['u00A0-'uD7FF'uF900-'uFDCF'uFDF0-'uFFEF])|(([a-z]|['u00A0-'uD7FF'uF900-'uFDCF'uFDF0-'uFFEF])([a-z]|'d|-|'.|_|~|['u00A0-'uD7FF'uF900-'uFDCF'uFDF0-'uFFEF])*([a-z]|['u00A0-'uD7FF'uF900-'uFDCF'uFDF0-'uFFEF])))'.?$/i);
        if ($('#contactVerify').length != 0)
        {
            var labelVerify = $('#contactForm label[for="contactVerify"]').text();
        }
        $('#contactForm button').click(function()
        {
            if ($('#contactName').val() == '')
            {
                $('#contactForm label[for="contactName"]').addClass('error').text(labelName + ' is required');
            }
            else
            {
                $('#contactForm label[for="contactName"]').removeClass('error').text(labelName);
            }
            if ($('#contactEmail').val() == '')
            {
                $('#contactForm label[for="contactEmail"]').addClass('error').text(labelEmail + ' is required');
            }
            else if (!emailPattern.test($('#contactEmail').val()))
            {
                $('#contactForm label[for="contactEmail"]').addClass('error').text(labelEmail + ' is invalid');
            }
            else
            {
                $('#contactForm label[for="contactEmail"]').removeClass('error').text(labelEmail);
            }
            if ($('#contactMessage').val() == '')
            {
                $('#contactForm label[for="contactMessage"]').addClass('error').text(labelMessage + ' is required');
            }
            else
            {
                $('#contactForm label[for="contactMessage"]').removeClass('error').text(labelMessage);
            }
            if (typeof labelVerify != 'undefined')
            {
                if ($('#contactVerify').val() == '')
                {
                    $('#contactForm label[for="contactVerify"]').addClass('error').text(labelVerify + ' is required');
                }
                else
                {
                    $('#contactForm label[for="contactVerify"]').removeClass('error').text(labelVerify);
                }
            }
            if ($('#contactForm label.error').length == 0)
            {
                $('#contactForm form').append('<input type="hidden" value="1" name="contactValid" />');
            }
            else
            {
                return false;
            }
        });
    }

我一直纠结于如何实现captcha验证。我是否将其包含在表单投递到的contact.php中？

或者我可以在表格张贴之前验证验证码吗？电子邮件地址是什么？

我试着添加：

<?php
session_start();
$cap = 'notEq';
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
    if (md5($_POST['contactVerify']) == $_SESSION['image_random_value']) {
        // contactVerify verification is Correct. Do something here!
        $cap = 'Eq';
    } else {
        // contactVerify verification is wrong. Take other action
        $cap = '';
    }
}
?>

到HTML表单的顶部。然后还添加：

var capch = '<?php echo $cap; ?>';
                if(capch != 'notEq'){
                    if(capch == 'Eq'){
        // My PHPMailer script //
                    }
                    else{
                        $('#contactForm label[for="contactVerify"]').addClass('error').text(labelVerify + ' is invalid');
                    }
                }                
            });

作为脚本。但是没有任何快乐。无论验证码是否无效，表格都会被发送。

感谢您的帮助。