/*
* 说明：生成随机码，并用图形方式显示随机码。
*/$ViewRandomCode = mt_rand(1000,10000);session_start();
$_SESSION['checksum'] = $ViewRandomCode;function set_4pixel($r, $g, $b, $x, $y)
{
global $sx, $sy, $pixels;$ofs = 3 * ($sx * $y + $x);
$pixels[$ofs] = chr($r);
$pixels[$ofs + 1] = chr($g);
$pixels[$ofs + 2] = chr($b);
$pixels[$ofs + 3] = chr($r);
$pixels[$ofs + 4] = chr($g);
$pixels[$ofs + 5] = chr($b);
$ofs += 3 * $sx;
$pixels[$ofs] =...