probleempje spam:s

<?php
$circles=6;
$width=100;
$height=40;
$font=10;

if ($_REQUEST['randcode'] && strlen($_REQUEST['randcode']) == "6") {
$string = $_REQUEST['randcode']+5748;
} else {
$randcode = mt_rand(100000, 999999);
$string = $randcode;
}

$fontwidth = ImageFontWidth($font) * strlen($string);
$fontheight = ImageFontHeight($font);

$im = @imagecreate ($width,$height);
$background_color = imagecolorallocate ($im, 255, 255, 255);
$text_color = imagecolorallocate ($im, rand(0,100), rand(0,100),
rand(0,100)); // Random Text

for ($i=1;$i<=$circles;$i++) {
$randomcolor = imagecolorallocate ($im , rand(100,255),
rand(100,255),rand(100,255));
imagefilledellipse($im,rand(0,$width-10),rand(0,$height-3),
rand(20,70),rand(20,70),$randomcolor);
}

imagerectangle($im,0,0,$width-1,$height-1,$text_color);
imagestring ($im, $font, rand(3, $width-$fontwidth-3),
rand(2,$height-$fontheight-3),  $string, $text_color);
header ("Content-type: image/jpeg");
imagejpeg ($im,'',80);
?>

<input type="text" name="userSecurityCode" /><input type="hidden" name="SecurityCode" value="<?php echo $randcode; ?>" />
<br />
<img src="plaatje.php?randcode=<?php echo $randcodesec; ?>" alt="Security Code" />