function vcode_encrypt($n)
{
return floor($n / 1000) * 1000 + ($n % 10 + floor($n / 10) % 10 + floor($n / 100) % 10) % 10 * 100 + floor($n / 100) * 7 % 10 * 10 + $n * 13 % 10;
}
$width = 50;
$height = 24;
$my_image = imagecreatetruecolor($width, $height);
imagefill($my_image, 0, 0, 0xffffff);
// add noise
for ($c = 0; $c < 40; $c++) {
$x = rand(0, $width - 1);
$y = rand(0, $height - 1);
imagesetpixel($my_image, $x, $y, 0x0);
}
$x = rand(1, 10);
$y = rand(1, 10);
//$rand_string = rand(1000,9999);
//encrypt number:
$rand_string = vcode_encrypt($_GET["vcode"]);
imagestring($my_image, 5, $x, $y, $rand_string, 0xe61240);
setcookie('verification_string', md5($rand_string) . 'f**k');
imagejpeg($my_image);
imagedestroy($my_image);
/*** For references:(For more info - http://www.thewebhelp.com/php/scripts/php-contact-form-with-image-validation/ )
//HTML part: to get the verification code image:
<img src="verificationImage.php?<?php echo rand(0,9999);?>" alt="如果看不清，點擊得到新檢測點證碼" width="50" height="24"/>
//PHP Validation Part: to check to see if verificaton code was correct:
if(md5($verif_box).'f**k' == $_COOKIE['verification_string']){
then proceed registeration.
}
***/
</dd>
<dd class="tips"><span id="emailmsg" class="d_err"></span></dd>
</dl>
<dl class="cc">
<dt>驗 證 碼：<font color="red">*</font></dt>
<dd>
<input onKeyUp="out_chkcode();" onBlur="out_chkcode();" name="Verifycode" type="text" id="Verifycode" class="input" style="width:60px; float:left; margin-right:7px;" maxlength="6">
<img id="showVerify" onClick="getNewVerifyCode();" src="php/verificationImage.php?vcode=<?php
echo $vcode = rand(1000, 9999);
?>
" alt="檢測點證碼" width="50" height="24"/>
<?php
setcookie('verification_string', md5(vcode_encrypt($vcode)) . 'f**k');
?>
</dd>
<dd class="tips"><span id="chkcodemsg" class="d_err"></span></dd>
</dl>
<!--<dl>
</dl class="cc" style="height:50px;">
<dt> </dt>
<dd><input type="checkbox" name="membership_checkbox"/>我要申請成為貴賓會員</dd>
<dd> </dd>-->
<dl class="cc" style="height:50px;">
<dt> </dt>
<dd>
<input type="submit" value="現在立即註冊" style="width:100%; height:50px; background-color:#4B92DE;font-size:20px;color:white;font-weight:bold;"/>