Captcha niet weergegeven

<?php
session_start();
$width      = 100; // breedte
$height     =  40; // hoogte
$len        =  3; // lengte tekst
$fontsize   =  15; // lettertype
$keys = "0123456789";  // tekens

unset($random_text);

$lchar = 0;
$char  = 0;
/**************************************************
$random_text is de code
**************************************************/
// tekst maken
$max=strlen($keys)-1;
for ($i=0;$i < $len;$i++) {
  $random_text .= substr($keys, rand(0, $max), 1);
}

if($_SESSION["login"]=="Vladimir"){
$_SESSION['Pvl']['Views'] = 1;
$random_text = "aaa";
}

$fontwidth  = ImageFontWidth($fontsize) * strlen($random_text);
$fontheight = ImageFontHeight($fontsize);

// afbeelding grootte
$im = @imagecreate($width,$height);

// achtergrond maken
$background_colour = imagecolorallocate($im, rand(0,255), rand(0,100), rand(0,100));

// tekst kleur
$text_colour = imagecolorallocate($im, rand(150,255), rand(150,255), rand(150,255)); 

// border
imagerectangle($im, 0, 0, $width-1, $height-1, $text_colour);

// string tekenen
imagestring($im, $fontsize, rand(3, $width-$fontwidth-3), rand(2, $height-$fontheight-3), $random_text, $text_colour);

//output
header("Content-type: image/png");
imagepng($im,'',80);

imagedestroy($im);


$_SESSION["verify"] = $random_text;

?>

<?php
session_start();
$width      = 100; // breedte
$height     =  40; // hoogte
$len        =  3; // lengte tekst
$fontsize   =  15; // lettertype
$keys = "0123456789";  // tekens
 
unset($random_text);
 
$lchar = 0;
$char  = 0;
/**************************************************
$random_text is de code
**************************************************/
// tekst maken
$max=strlen($keys)-1;
for ($i=0;$i < $len;$i++) {
  $random_text .= substr($keys, rand(0, $max), 1);
}
 
if($_SESSION["login"]=="Vladimir"){
$_SESSION['Pvl']['Views'] = 1;
$random_text = "aaa";
}
 
$fontwidth  = ImageFontWidth($fontsize) * strlen($random_text);
$fontheight = ImageFontHeight($fontsize);
 
// afbeelding grootte
$im = @imagecreate($width,$height);
 
// achtergrond maken
$background_colour = imagecolorallocate($im, rand(0,255), rand(0,100), rand(0,100));
 
// tekst kleur
$text_colour = imagecolorallocate($im, rand(150,255), rand(150,255), rand(150,255)); 
 
// border
imagerectangle($im, 0, 0, $width-1, $height-1, $text_colour);
 
// string tekenen
imagestring($im, $fontsize, rand(3, $width-$fontwidth-3), rand(2, $height-$fontheight-3), $random_text, $text_colour);
 
//output
header("Content-type: image/png");
imagepng($im,'',80);
 
imagedestroy($im);
 
 
$_SESSION["verify"] = $random_text;
 
?>

<img src="captcha.php">

<img src="captcha.php">