Credit card verification procedure

& Lt ;? Php & nbsp; Creditcardvalidationroutine> May15, 2000
//////////////////////////////////////// ////////////
////
// Credit card validation routine //
// May 15,200 0 //
// 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 |! Ereg ('5 [1-5] ', $ cardnumber) return 0;
}
Elseif ($ cardtype = 'visa '){
If (strlen ($ cardnumber )! = 13 & strlen ($ cardnumber )! = 16) | substr ($ cardnumber, 0, 1 )! = '4 ')

Return 0;
}
Elseif ($ cardtype = 'amx '){
If (strlen ($ cardnumber )! = 15 |! Ereg ('3 [47] ', $ cardnumber) return;
}
Elseif ($ cardtype = 'discover '){
If (strlen ($ cardnumber )! = 16 | substr ($ cardnumber, 0, 4 )! = '20140901') return 0;
}
Else {
// Invalid type entered
Return-1;
}


// Start MOD 10 checks

$ Dig = toCharArray ($ cardnumber );
$ Numdig = sizeof ($ dig );
$ IntIntJ = 0;
For ($ intI = ($ numdig-2); $ intI> = 0; $ intI-= 2 ){
$ Dbl [$ intIntJ] = $ dig [$ intI] * 2;
$ IntIntJ ++;
}
$ Dblsz = sizeof ($ dbl );
$ Validate = 0;
For ($ intI = 0; $ intI <$ dblsz; $ intI ++ ){
$ Add = toCharArray ($ dbl [$ intI]);
For ($ intIntJ = 0; $ intIntJ $ Validate + = $ add [$ intIntJ];
}
$ Add = '';
}
For ($ intI = ($ numdig-1); $ intI> = 0; $ intI-= 2 ){
$ Validate + = $ dig [$ intI];
}
If (substr ($ validate,-1, 1) = '0') return 1;
Else return 0;
}


// Takes a string and returns an array of characters

Function toCharArray ($ intInput ){
$ Len = strlen ($ intInput );
For ($ intIntJ = 0; $ intIntJ <$ len; $ intIntJ ++ ){
$ Char [$ intIntJ] = substr ($ intInput, $ intIntJ, 1 );
}
Return ($ char );
}

?>