【急】图片验证码破解后，如何同步提交并返回数据？

引用:

<?
//img.php
session_start();
//生成四位随机整数验证码
mt_srand((double)microtime()*1000000);
$AuthNum = mt_rand();
if($AuthNum<1000){$AuthNum *= 1000;}
$AuthNum = substr(strrev($AuthNum),-4);
session_register('AuthNum');
$_SESSION['AuthNum'] = md5($AuthNum);
//echo $_SESSION['AuthNum'];
Header("Content-type:image/png");
$im = ImageCreate(60,20);
$black = ImageColorAllocate($im,0,0,0);
$white = ImageColorAllocate($im,255,255,255);
$white2 = ImageColorAllocate($im,255,0,0);

//将四位整数验证码绘入图片
//位置交错
for ($i = 0; $i < 4; $i++) {
if ($i%2 == 0){$top = 1;}else{$top = 3;}
imagestring($im, 5, 10*$i+11, $top, substr($AuthNum,$i,1), $white);
}

//加入干扰象素线
//ImageLine($im,0,11,40,6,$white2);
//加入干扰象素点
for($i=0;$i<150;$i++){ imagesetpixel($im, rand()%70 , rand()%30 , $white2); }
ImagePng($im);
ImageDestroy($im);
?>