<?
/* Validates Credit Card Numbers. */
Function vlen () 
{
global $f_strCardNum,$f_strCreditCard,$g_intCardLength,$g_arrCreditCard;

if(($g_intCardLength == 13) or ($g_intCardLength == 16)) 
   {
   vver();
	} 
else 
   {
   invalid_cc();
   }
}


Function mclen () 
{
global $f_strCardNum,$f_strCreditCard,$g_intCardLength,$g_arrCreditCard;

if($g_intCardLength == 16) 
   {
   ver16();
   } 
   else 
   {
   invalid_cc();
   }
}

Function alen () 
{
global $f_strCardNum,$f_strCreditCard,$g_intCardLength,$g_arrCreditCard;

if($g_intCardLength == 15) 
   {
   ver15();
   } 
else 
   {
   invalid_cc();
   }
}


Function nlen () 
{
global $f_strCardNum,$f_strCreditCard,$g_intCardLength,$g_arrCreditCard;

if($g_intCardLength == 16) 
   {
   ver16();
   } 
else 
   {
   invalid_cc();
   }
}


Function olen () 
{
global $f_strCardNum,$f_strCreditCard,$g_intCardLength,$g_arrCreditCard;

if($g_intCardLength > 12) 
   {
   ocheck();
   } 
else 
   {
   invalid_cc();
   }
}


// pick one for Visa
Function vver () 
{
global $f_strCardNum,$f_strCreditCard,$g_intCardLength,$g_arrCreditCard;

if($g_intCardLength == 13) 
   { 
   ver13(); 
   }
elseif($g_intCardLength == 16) 
   { 
   ver16(); 
   }
}


// For 13 digit cards
Function ver13 () 
{
global $f_strCardNum,$f_strCreditCard,$g_intCardLength,$g_arrCreditCard;

$intCCard1a  = $g_arrCreditCard[1] * 2;
$intCCard3a  = $g_arrCreditCard[3] * 2;
$intCCard5a  = $g_arrCreditCard[5] * 2;
$intCCard7a  = $g_arrCreditCard[7] * 2;
$intCCard9a  = $g_arrCreditCard[9] * 2;
$intCCard11a = $g_arrCreditCard[11] * 2;

if($intCCard1a >= 10) 
   {
   $intCCard1b = substr($intCCard1a, 0, 1);
   $intCCard1c = substr($intCCard1a, 1, 1);
   $intCCard1 = $intCCard1b + $intCCard1c;
   } 
else 
   {
   $intCCard1 = $intCCard1a;
   }
if($CreditCard3a >= 10) 
   {
   $intCCard3b = substr($intCCard3a, 0, 1);
   $intCCard3c = substr($intCCard3a, 1, 1);
   $g_arrCreditCard[3] = $intCCard3b + $intCCard3c;
   } 
else 
   {
   $g_arrCreditCard[3] = $intCCard3a;
   }
if($intCCard5a >= 10) 
   {
   $intCCard5b = substr($intCCard5a, 0, 1);
   $intCCard5c = substr($intCCard5a, 1, 1);
   $g_arrCreditCard[5] = $intCCard5b + $intCCard5c;
   } 
else 
   {
   $g_arrCreditCard[5] = $intCCard5a;
   }
if($intCCard7a >= 10) 
   {
   $intCCard7b = substr($intCCard7a, 0, 1);
   $intCCard7c = substr($intCCard7a, 1, 1);
   $g_arrCreditCard[7] = $intCCard7b + $intCCard7c;
   } 
else 
   {
   $g_arrCreditCard[7] = $intCCard7a;
   }
if($intCCard9a >= 10) 
   {
   $intCCard9b = substr($intCCard9a, 0, 1);
   $intCCard9c = substr($intCCard9a, 1, 1);
   $g_arrCreditCard[9] = $intCCard9b + $intCCard9c;
   } 
else 
   {
   $g_arrCreditCard[9] = $intCCard9a;
   }
if($intCCard11a >= 10) 
   {
   $intCCard11b = substr($intCCard11a, 0, 1);
   $intCCard11c = substr($intCCard11a, 1, 1);
   $g_arrCreditCard[11] = $intCCard11b + $intCCard11c;
   } 
else 
   {
   $g_arrCreditCard[11] = $intCCard11a;
   }
$strVal = $g_arrCreditCard[0] + $g_arrCreditCard[1] + $g_arrCreditCard[2] +  $g_arrCreditCard[3]  +
          $g_arrCreditCard[4] + $g_arrCreditCard[5] + $g_arrCreditCard[6] +  $g_arrCreditCard[7]  +
          $g_arrCreditCard[8] + $g_arrCreditCard[9] + $g_arrCreditCard[10] + $g_arrCreditCard[11] +
          $g_arrCreditCard[12];
if(substr($strVal,1,1) !=0 ) 
   {
   invalid_cc();
   }
}


// For 16 digit cards
Function ver16 () 
{
global $f_strCardNum,$f_strCreditCard,$g_intCardLength,$g_arrCreditCard;

$intCCard0a = $g_arrCreditCard[0] * 2;
$intCCard2a = $g_arrCreditCard[2] * 2;
$intCCard4a = $g_arrCreditCard[4] * 2;
$intCCard6a = $g_arrCreditCard[6] * 2;
$intCCard8a = $g_arrCreditCard[8] * 2;
$intCCard10a = $g_arrCreditCard[10] * 2;
$intCCard12a = $g_arrCreditCard[12] * 2;
$intCCard14a = $g_arrCreditCard[14] * 2;
if($intCCard0a >= 10) 
   {
   $intCCard0b = substr($intCCard0a, 0, 1);
   $intCCard0c = substr($intCCard0a, 1, 1);
   $g_arrCreditCard[0] = $intCCard0b + $intCCard0c;
   } 
else 
   {
   $g_arrCreditCard[0] = $intCCard0a;
   }
if($intCCard2a >= 10) 
   {
   $intCCard2b = substr($intCCard2a, 0, 1);
   $intCCard2c = substr($intCCard2a, 1, 1);
   $g_arrCreditCard[2] = $intCCard2b + $intCCard2c;
   } 
else 
   {
   $g_arrCreditCard[2] = $intCCard2a;
   }
if($intCCard4a >= 10) 
   {
   $intCCard4b = substr($intCCard4a, 0, 1);
   $intCCard4c = substr($intCCard4a, 1, 1);
   $g_arrCreditCard[4] = $intCCard4b + $intCCard4c;
   } 
else 
   {
   $g_arrCreditCard[4] = $intCCard4a;
   }
if($intCCard6a >= 10) 
   {
   $intCCard6b = substr($intCCard6a, 0, 1);
   $intCCard6c = substr($intCCard6a, 1, 1);
   $g_arrCreditCard[6] = $intCCard6b + $intCCard6c;
   } 
else 
   {
   $g_arrCreditCard[6] = $intCCard6a;
   }
if($intCCard8a >= 10) 
   {
   $intCCard8b = substr($intCCard8a, 0, 1);
   $intCCard8c = substr($intCCard8a, 1, 1);
   $g_arrCreditCard[8] = $intCCard8b + $intCCard8c;
   } 
else 
   {
   $g_arrCreditCard[8] = $intCCard8a;
   }
if($intCCard10a >= 10) 
   {
   $intCCard10b = substr($intCCard10a, 0, 1);
   $intCCard10c = substr($intCCard10a, 1, 1);
   $g_arrCreditCard[10] = $intCCard10b + $intCCard10c;
   } 
else 
   {
   $g_arrCreditCard[10] = $intCCard10a;
   }
if($intCCard12a >= 10) 
   {
   $intCCard12b = substr($intCCard12a, 0, 1);
   $intCCard12c = substr($intCCard12a, 1, 1);
   $g_arrCreditCard[12] = $intCCard12b + $intCCard12c;
   } 
else 
   {
   $g_arrCreditCard[12] = $intCCard12a;
   }
if($intCCard14a >= 10) 
   {
   $intCCard14b = substr($intCCard14a, 0, 1);
   $intCCard14c = substr($intCCard14a, 1, 1);
   $g_arrCreditCard[14] = $intCCard14b + $intCCard14c;
   } 
else 
   {
   $g_arrCreditCard[14] = $intCCard14a;
   }
$strVal = $g_arrCreditCard[0] +  $g_arrCreditCard[1] +  $g_arrCreditCard[2] +  $g_arrCreditCard[3]  + 
          $g_arrCreditCard[4] +  $g_arrCreditCard[5] +  $g_arrCreditCard[6] +  $g_arrCreditCard[7]  +
          $g_arrCreditCard[8] +  $g_arrCreditCard[9] +  $g_arrCreditCard[10] + $g_arrCreditCard[11] +
          $g_arrCreditCard[12] + $g_arrCreditCard[13] + $g_arrCreditCard[14] + $g_arrCreditCard[15];
if(substr($strVal,1,1) !=0 ) 
   {
   invalid_cc();
   }
}


// For 15 digit (Amex) cards
Function ver15 () 
{
global $f_strCardNum,$f_strCreditCard,$g_intCardLength,$g_arrCreditCard;

$intCCard1a = $g_arrCreditCard[1] * 2;
$intCCard3a = $g_arrCreditCard[3] * 2;
$intCCard5a = $g_arrCreditCard[5] * 2;
$intCCard7a = $g_arrCreditCard[7] * 2;
$intCCard9a = $g_arrCreditCard[9] * 2;
$intCCard11a = $g_arrCreditCard[11] * 2;
$intCCard13a = $g_arrCreditCard[13] * 2;
if($intCCard1a >= 10) 
   {
   $intCCard1b = substr($intCCard1a,0,1);
   $intCCard1c = substr($intCCard1a,1,1);
   $g_arrCreditCard[1] = $intCCard1b + $intCCard1c;
   } 
else 
   {
   $g_arrCreditCard[1] = $intCCard1a;
   }
if($intCCard3a >= 10) 
   {
   $intCCard3b = substr($intCCard3a,0,1);
   $intCCard3c = substr($intCCard3a,1,1);
   $g_arrCreditCard[3] = $intCCard3b + $intCCard3c;
   } 
else 
   {
   $g_arrCreditCard[3] = $intCCard3a;
   }
if($intCCard5a >= 10) 
   {
   $intCCard5b = substr($intCCard5a,0,1);
   $intCCard5c = substr($intCCard5a,1,1);
   $g_arrCreditCard[5] = $intCCard5b + $intCCard5c;
   } 
else 
   {
   $g_arrCreditCard[5] = $intCCard5a;
   }
if($intCCard7a >= 10) 
   {
   $intCCard7b = substr($intCCard7a,0,1);
   $intCCard7c = substr($intCCard7a,1,1);
   $g_arrCreditCard[7] = $intCCard7b + $intCCard7c;
   } 
else 
   {
   $g_arrCreditCard[7] = $intCCard7a;
   }
if($intCCard9a >= 10) 
   {
   $intCCard9b = substr($intCCard9a,0,1);
   $intCCard9c = substr($intCCard9a,1,1);
   $g_arrCreditCard[9] = $intCCard9b + $intCCard9c;
   } 
else 
   {
   $g_arrCreditCard[9] = $intCCard9a;
   }
if($intCCard11a >= 10) 
   {
   $intCCard11b = substr($intCCard11a,0,1);
   $intCCard11c = substr($intCCard11a,1,1);
   $g_arrCreditCard[11] = $intCCard11b + $intCCard11c;
   } 
else 
   {
   $g_arrCreditCard[11] = $intCCard11a;
   }
if($intCCard13a >= 10) 
   {
   $intCCard13b = substr($intCCard13a,0,1);
   $intCCard13c = substr($intCCard13a,1,1);
   $g_arrCreditCard[13] = $intCCard13b + $intCCard13c;
   } 
else 
   {
   $g_arrCreditCard[13] = $intCCard13a;
   }
$strVal = $g_arrCreditCard[0] +  $g_arrCreditCard[1] +  $g_arrCreditCard[2]  + $g_arrCreditCard[3]  +
          $g_arrCreditCard[4] +  $g_arrCreditCard[5] +  $g_arrCreditCard[6]  + $g_arrCreditCard[7]  +
          $g_arrCreditCard[8] +  $g_arrCreditCard[9] +  $g_arrCreditCard[10] + $g_arrCreditCard[11] +
          $g_arrCreditCard[12] + $g_arrCreditCard[13] + $g_arrCreditCard[14];
if(substr($strVal,1,1) !=0 ) 
   {
   invalid_cc();
   }
}


Function ocheck () 
{
global $f_strCardNum,$f_strCreditCard,$g_intCardLength,$g_arrCreditCard;

for($intI = 0; $intI < $g_intCardLength - 1; $intI++) 
   {
   $intWeight = substr($f_strCardNum, -1 * ($intI + 2), 1) * (2 - ($intI % 2));
   $intSum += (($intWeight < 10) ? $intWeight : ($intWeight - 9));
   }
if(substr($f_strCardNum, -1) != (10 - $intSum % 10) % 10) 
   {
   invalid_cc();
   }
}
 

Function invalid_cc () 
{
global $g_blnValid, $g_strErrExternal, $g_strErrInternal;

$g_blnValid = false;
$g_strErrExternal = "Your Credit Card Number is Invalid."; 
$g_strErrInternal = "Your Credit Card Number is Invalid";
}

?>