devluis/demo.php

## demo.php
<?php
session_start();
$_SESSION['count'] = time();
$image;
?>

<title>demo.php</title>
<body style="background-color:#ddd; ">

<?php
$flag = 5;
if (isset($_POST["flag"])) {
    $input = $_POST["input"];
    $flag = $_POST["flag"];
}

if ($flag == 1) {
    if ($input == $_SESSION['captcha_string']) {
        ?>

        <div style="text-align:center;">
            <h1>Your answer is correct!</h1>

            <form action=" <?php echo $_SERVER['PHP_SELF']; ?>" method="POST">
                <input type="submit" value="refresh the page">
            </form>
        </div>

    <?php

    } else {
        ?>

        <div style="text-align:center;">
            <h1>Your answer is incorrect!<br>please try again </h1>
        </div>

        <?php
        create_image();
        display();
    }
} else {
    create_image();
    display();
}

function display()
{
    ?>

    <div style="text-align:center;">
        <h3>TYPE THE TEXT YOU SEE IN THE IMAGE</h3>
        <b>This is just to check if you are a robot</b>

        <div style="display:block;margin-bottom:20px;margin-top:20px;">
            <img src="image<?php echo $_SESSION['count'] ?>.png">
        </div>
        <form action=" <?php echo $_SERVER['PHP_SELF']; ?>" method="POST"
        / >
        <input type="text" name="input"/>
        <input type="hidden" name="flag" value="1"/>
        <input type="submit" value="submit" name="submit"/>
        </form>

        <form action=" <?php echo $_SERVER['PHP_SELF']; ?>" method="POST">
            <input type="submit" value="refresh the page">
        </form>
    </div>

<?php
}

function  create_image()
{
    global $image;
    $image = imagecreatetruecolor(200, 50) or die("Cannot Initialize new GD image stream");

    $background_color = imagecolorallocate($image, 255, 255, 255);
    $text_color = imagecolorallocate($image, 0, 255, 255);
    $line_color = imagecolorallocate($image, 64, 64, 64);
    $pixel_color = imagecolorallocate($image, 0, 0, 255);

    imagefilledrectangle($image, 0, 0, 200, 50, $background_color);

    for ($i = 0; $i < 3; $i++) {
        imageline($image, 0, rand() % 50, 200, rand() % 50, $line_color);
    }

    for ($i = 0; $i < 1000; $i++) {
        imagesetpixel($image, rand() % 200, rand() % 50, $pixel_color);
    }


    $letters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
    $len = strlen($letters);
    $letter = $letters[rand(0, $len - 1)];

    $text_color = imagecolorallocate($image, 0, 0, 0);
    $word = "";
    for ($i = 0; $i < 6; $i++) {
        $letter = $letters[rand(0, $len - 1)];
        imagestring($image, 7, 5 + ($i * 30), 20, $letter, $text_color);
        $word .= $letter;
    }
    $_SESSION['captcha_string'] = $word;

    $images = glob("*.png");
    foreach ($images as $image_to_delete) {
        @unlink($image_to_delete);
    }
    imagepng($image, "image" . $_SESSION['count'] . ".png");

}

?>
</body>
	<?php
	session_start();
	$_SESSION['count'] = time();
	$image;
	?>

	<title>demo.php</title>
	<body style="background-color:#ddd; ">

	<?php
	$flag = 5;
	if (isset($_POST["flag"])) {
	$input = $_POST["input"];
	$flag = $_POST["flag"];
	}

	if ($flag == 1) {
	if ($input == $_SESSION['captcha_string']) {
	?>

	<div style="text-align:center;">
	<h1>Your answer is correct!</h1>

	<form action=" <?php echo $_SERVER['PHP_SELF']; ?>" method="POST">
	<input type="submit" value="refresh the page">
	</form>
	</div>

	<?php

	} else {
	?>

	<div style="text-align:center;">
	<h1>Your answer is incorrect!<br>please try again </h1>
	</div>

	<?php
	create_image();
	display();
	}
	} else {
	create_image();
	display();
	}

	function display()
	{
	?>

	<div style="text-align:center;">
	<h3>TYPE THE TEXT YOU SEE IN THE IMAGE</h3>
	<b>This is just to check if you are a robot</b>

	<div style="display:block;margin-bottom:20px;margin-top:20px;">
	<img src="image<?php echo $_SESSION['count'] ?>.png">
	</div>
	<form action=" <?php echo $_SERVER['PHP_SELF']; ?>" method="POST"
	/ >
	<input type="text" name="input"/>
	<input type="hidden" name="flag" value="1"/>
	<input type="submit" value="submit" name="submit"/>
	</form>

	<form action=" <?php echo $_SERVER['PHP_SELF']; ?>" method="POST">
	<input type="submit" value="refresh the page">
	</form>
	</div>

	<?php
	}

	function create_image()
	{
	global $image;
	$image = imagecreatetruecolor(200, 50) or die("Cannot Initialize new GD image stream");

	$background_color = imagecolorallocate($image, 255, 255, 255);
	$text_color = imagecolorallocate($image, 0, 255, 255);
	$line_color = imagecolorallocate($image, 64, 64, 64);
	$pixel_color = imagecolorallocate($image, 0, 0, 255);

	imagefilledrectangle($image, 0, 0, 200, 50, $background_color);

	for ($i = 0; $i < 3; $i++) {
	imageline($image, 0, rand() % 50, 200, rand() % 50, $line_color);
	}

	for ($i = 0; $i < 1000; $i++) {
	imagesetpixel($image, rand() % 200, rand() % 50, $pixel_color);
	}


	$letters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
	$len = strlen($letters);
	$letter = $letters[rand(0, $len - 1)];

	$text_color = imagecolorallocate($image, 0, 0, 0);
	$word = "";
	for ($i = 0; $i < 6; $i++) {
	$letter = $letters[rand(0, $len - 1)];
	imagestring($image, 7, 5 + ($i * 30), 20, $letter, $text_color);
	$word .= $letter;
	}
	$_SESSION['captcha_string'] = $word;

	$images = glob("*.png");
	foreach ($images as $image_to_delete) {
	@unlink($image_to_delete);
	}
	imagepng($image, "image" . $_SESSION['count'] . ".png");

	}

	?>
	</body>