CODEWITHSUNDEEP
phpajaxcaptcha
Masa
Masa

Reputation: 300

refreshing captcha code using Ajax

In my page I have an img that shows captcha code and one img that refreshes the captcha code, not whole page, when clicked. in chrome it works very well and refreshes the code every time it is clicked, but in IE nothing happens when the img is clicked and for refreshing the captcha code you have to reload the page.
how can I solve this problem in IE?

<img name="capImg" id="capImg" src="php/captcha.php">
<img src="images/recaptcha.png" onClick="resetCap();">

script:

function resetCap(){
    var ajaxRequest;
    try{
        ajaxRequest = new XMLHttpRequest();
    } catch (e){
        try{
            ajaxRequest = new ActiveXObject("Msxml2.XMLHTTP");
        } catch (e) {
            try{
                ajaxRequest = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e){
                return false;
            }
        }
    }
    ajaxRequest.onreadystatechange = function(){
        if(ajaxRequest.readyState == 4 && ajaxRequest.status == 200){
            document.getElementById('capImg').src = "php/captcha.php";
        }
    }
    ajaxRequest.open("GET", "php/captcha.php", true);
    ajaxRequest.send();
}

captcha.php:

<?php
session_start();
$backImage = imagecreatefrompng('C:\xampp\htdocs\service\images\captchaBack.png');
$shadowColor = imagecolorallocate($backImage, 150, 150, 150);
$textColor = imagecolorallocate($backImage, 50, 50, 50);
$font_path = 'C:\xampp\htdocs\service\fonts\times_new_yorker.ttf';
$text = NULL;
for($i=0; $i<6; $i++) $text .= mt_rand(0,9);
$_SESSION['capCode'] = $text;
imagettftext($backImage, 28, 2, 13, 38, $shadowColor, $font_path, $text);
imagettftext($backImage, 28, 2, 15, 40, $textColor, $font_path, $text);

header('Content-type: image/png');

imagepng($backImage);
imagedestroy($backImage);
?>

Upvotes: 0

Views: 99

Answers (1)

user4035
user4035

Reputation: 23729

Use a unique parameter that will make browser retrieve the image again and not look into the cache. You don't need Ajax here:

function resetCap(){
    document.getElementById('capImg').src = 
                           "php/captcha.php?" + new Date().getTime();  
}

This is all you need.

Upvotes: 1

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