帮助文档里的事例输出乱码 请求教,该怎么处理

帮助文档里的事例输出乱码 请求教
这是从帮助文档上考下来的事例 但为什么输出是乱码呢 怎么解决

PHP code

<!--Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/--><?php header("Content-type: image/jpeg");  $im = imagecreate(400,30);  $white = imagecolorallocate($im, 255,255,255);  $black = imagecolorallocate($im, 0,0,0);  // Replace path by your own font path  imagettftext($im, 20, 0, 10, 20, $black, "/path/arial.ttf",  "Testing... Omega: &#937;");  imagejpeg($im);  imagedestroy($im);?>

输出结果:

Warning: imagettftext() [function.imagettftext]: Invalid font filename in F:\wamp\www\bkqs\imageCode\file.php on line 9
??JFIF?>CREATOR: gd-jpeg v1.0 (using IJG JPEG v62), default quality ?C $.' ",#(7),01444'9=82<.342>