信用卡效验程序

<?php  

////////////////////////////////////////////////////  
//                                                //   
// Credit card validation routine                 //  
// May 15, 2000                                   //  
// By ariso                                       //  
// validateCardCode($number[,$cardtype])          //  
////////////////////////////////////////////////////  


function validateCardCode($cardnumber, $cardtype =  'unknown')
{  
     //Clean up input  

    $cardtype = strtolower($cardtype);  
    $cardnumber = ereg_replace( '[-[:space:]]',  '',$cardnumber);   

     //Do type specific checks  

    if ($cardtype ==  'unknown') {  
         //Skip type specific checks  
    }  
    elseif ($cardtype ==  'mastercard'){  
        if (strlen($cardnumber) != 16

关键词：信用卡效验程序