想請問為什麼我的驗證碼會跑不出來？

<?php include 'inc/inc_set.php'; ?>
<?php
header("Content-Type: image/png");
$im = @imagecreate(110, 35) //(圖形寬度,圖形高度)
    or die("Cannot Initialize new GD image stream");

$bg_color1 = mt_rand(0, 100);
$bg_color2 = mt_rand(100, 255);    
$bg_color3 = mt_rand(0, 255);
$background_color = imagecolorallocate($im, 0, 0, 0);

$grey = imagecolorallocate($im, 255, 255, 255);
$red = imagecolorallocate($im, 255, 0, 0);
$green = imagecolorallocate($im, 0, 255, 0);
$color0 = imagecolorallocate($im, 0, 0, 255);
$color1 = imagecolorallocate($im, 100, 100, 100);
$color2= imagecolorallocate($im, 0, 100, 0);
$color3 = imagecolorallocate($im, 0, 0, 100);
$color4 = imagecolorallocate($im, 100, 52, 44);
$color_arr=array($grey, $red, $green, $color1);

$rtext = mt_rand(10000, 99999);
$_SESSION[$g_proj."rand"] = $rtext;	
$font1 = '/local/htdocs'.$g_proj.'/font/DroidSans.ttf';
$font2 = '/local/htdocs'.$g_proj.'/font/UbuntuMono-R.ttf';
$font3 = '/local/htdocs'.$g_proj.'/font/XeroxSansSerifWideBoldOblique.ttf';
$font4 = '/local/htdocs'.$g_proj.'/font/XeroxSerifNarrow.ttf';
$font_arr=array($font1, $font2, $font4);

$color1=$color_arr[mt_rand(0, sizeof($color_arr)-1)];
$color2=$color_arr[mt_rand(0, sizeof($color_arr)-1)];
while ($color1==$background_color)
	$color1=$color_arr[mt_rand(0, sizeof($color_arr)-1)];
while ($color2==$color1 || $color2==$background_color)
	$color2=$color_arr[mt_rand(0, sizeof($color_arr)-1)];

$shadow_r = mt_rand(0, 8);
$shadow_r2 = mt_rand(0, 4);
imagettftext($im, 26+$shadow_r2, 0+$shadow_r, 2+$shadow_r, 28+$shadow_r, $color1, $font_arr[mt_rand(0, sizeof($font_arr)-1)], $rtext);

$shadow_rr = mt_rand(0, 8);
$shadow_rr2 = mt_rand(0, 4);
$shadow_rrr = mt_rand(-10, 10);
$shadow_rrrr = mt_rand(10, 28);

imagettftext($im, 26+$shadow_rr2, $shadow_rrr, 2+$shadow_rr, 10+$shadow_rrrr, $color2, $font_arr[mt_rand(0, sizeof($font_arr)-1)], $rtext);

for ($i = 0; $i < 5000; $i++) {
	$pink = imagecolorallocate($im, mt_rand(100,255), mt_rand(0,100), mt_rand(100, 200));
	imagesetpixel($im, mt_rand(0,200), mt_rand(0,200), $pink);
}
 

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