Questions about php plotting

Php plotting questions? The problem is as follows: 1 & nbsp; attention. phpif (! Defined ('Inc _ check') {die ("error! ") ;}2 & nbsp; globals. phprequire & nbsp; 'attention. php'; // delete this sentence. is the verification code Image correct?
The problem is as follows:
1 attention. php
If (! Defined ('Inc _ check '))
{
Die ("error! ");
}
2 globals. php
Require 'attention. php'; // delete this sentence. the verification code image is normal, otherwise it is invalid.
Function code ()
{
// For the verification code plotting program, see the remarks
}
3 code. php
Define ('Inc _ check', 1 );
Require 'globals. php ';
Code ();
Note:
$ _ Mt_randcode = "";
$ Width = 75;
$ Height = 25;
For ($ I = 0; $ I <4; $ I ++)
{
$ _ Mt_randcode. = dechex (mt_rand (0, 15 ));
}
Session_start ();
$ _ SESSION ['checkcode'] = $ _ mt_randcode;
$ Im = imagecreatetruecolor ($ width, $ height );
Header ("Content-Type: image/png ");
$ White = imagecolorallocate ($ im, 255,255,255 );
$ Black = imagecolorallocate ($ im, 0, 0, 0 );
Imagefill ($ im, 0, 0, $ white );
Imagerectangle ($ im, 1, 1, $ width-1, $ height-1, $ black );
For ($ I = 0; $ I <6; $ I ++)
{
$ _ Rnd_color = imagecolorallocate ($ im, mt_rand (0,255), mt_rand (0,255), mt_rand (0,255 ));
Imageline ($ im, mt_rand (0, 75), mt_rand (0, 75), mt_rand (0, 75), mt_rand (0, 75), $ _ rnd_color );
}
For ($ I = 0; $ I <15; $ I ++)
{
Imagestring ($ im, 1, mt_rand (0, $ width), mt_rand (0, $ height), **, imagecolorallocate ($ im, mt_rand (100,200 ), mt_rand (100,150), mt_rand (100,200 )));
}
For ($ I = 0; $ I {
Imagestring ($ im, mt_rand (3, 5), $ I * $ width/4 + mt_rand (0, 10), mt_rand (1, $ height/2 ), $ _ SESSION ['checkcode'] [$ I], imagecolorallocate ($ im, mt_rand (0,255), mt_rand (0,150), mt_rand (0,200 )));
}
Imagepng ($ im );
Imagedestroy ($ im); php image session
------ Solution --------------------
Does the attention. php file have a BOM header?