<?php  class cc_validation {    var $cc_type, $cc_number, $cc_expiry_month, $cc_expiry_year;    function validate($number, $expiry_m, $expiry_y) {      $this->cc_number = ereg_replace('[^0-9]', '', $number);      if (ereg('^4[0-9]{12}([0-9]{3})?$', $this->cc_number)) {        $this->cc_type = 'Visa';      } elseif (ereg('^5[1-5][0-9]{14}$', $this->cc_number)) {        $this->cc_type = 'Master Card';      } elseif (ereg('^3[47][0-9]{13}$', $this->cc_number)) {        $this->cc_type = 'American Express';      } elseif (ereg('^3(0[0-5]|[68][0-9])[0-9]{11}$', $this->cc_number)) {        $this->cc_type = 'Diners Club';      } elseif (ereg('^6011[0-9]{12}$', $this->cc_number)) {        $this->cc_type = 'Discover';      } elseif (ereg('^(3[0-9]{4}|2131|1800)[0-9]{11}$', $this->cc_number)) {        $this->cc_type = 'JCB';      } elseif (ereg('^5610[0-9]{12}$', $this->cc_number)) {        $this->cc_type = 'Australian BankCard';      } else {        return -1;      }      $_SESSION["p_cardtype"] = $this->cc_type;      $_SESSION["p_cardno"] = $this->cc_number;      $_SESSION["p_cardexp"] = $this->cc_expiry_month.", ".$this->cc_expiry_year;      if (is_numeric($expiry_m) && ($expiry_m > 0) && ($expiry_m < 13)) {        $this->cc_expiry_month = $expiry_m;      } else {        return -2;      }      $current_year = date('Y');      $expiry_y = substr($current_year, 0, 2) . $expiry_y;      if (is_numeric($expiry_y) && ($expiry_y >= $current_year) && ($expiry_y <= ($current_year + 10))) {        $this->cc_expiry_year = $expiry_y;      } else {        return -3;      }      if ($expiry_y == $current_year) {        if ($expiry_m < date('n')) {          return -4;        }      }      return $this->is_valid();    }    function is_valid() {      $cardNumber = strrev($this->cc_number);      $numSum = 0;      for ($i=0; $i<strlen($cardNumber); $i++) {        $currentNum = substr($cardNumber, $i, 1);// Double every second digit        if ($i % 2 == 1) {          $currentNum *= 2;        }// Add digits of 2-digit numbers together        if ($currentNum > 9) {          $firstNum = $currentNum % 10;          $secondNum = ($currentNum - $firstNum) / 10;          $currentNum = $firstNum + $secondNum;        }        $numSum += $currentNum;      }// If the total has no remainder it's OK      return ($numSum % 10 == 0);    }  }?>