function begin()
  {
  var t=0;

  for (var i = 0; i < document.PaymentForm.CardCu.length; i++)
    if (document.PaymentForm.CardCu.options[i].value=="CMR")
      t=i;
  document.PaymentForm.CardCu.options[t].selected=true;
}

function ValidCard(CreditCard){
// Valid Input Syntax:
// Type1: **************** (16 columns)
// Type2: **** **** **** **** (19)
// Type3: ****-****-****-**** (19)
// Input is a credit card number in the form of a string.
// Validates numbers which use a "double-add-double MOD 10"
// check digit Output is False if not valid, True if valid.

var Validity = false;       // Assume invalid card
var LN = CreditCard.length;	 // Get input value length

  if ((16 <= LN) && (LN <= 19)){
    LN --;
    CheckSum = 0;	// start with 0 checksum
    Dbl = false;	// Start with a non-doubling

    //------------------------------------------------------------
    //	Beginning backward loop through string
    //-------------------------------------------------------------

    for (Idx = LN; Idx >= 0; Idx --){
	Digit = CreditCard.substr(Idx, 1);	  // Isolate character
	if (("0" <= Digit && Digit <= "9")
             || Digit == " " || Digit == "-"){
	    if (Digit != " " && Digit != "-"){ // Skip connector
		Digit -= "0";	  // Remove ASCII bias
		if (Dbl){		  // If in the "double-add" phase
		    Digit += Digit; // Then double first
		    if (Digit > 9){ // Cast nines
			Digit -= 9;
		    }
		}
		Dbl = !Dbl; // Flip doubling flag
		CheckSum += Digit;  // Add to running sum
		if (CheckSum > 9){  // Cast tens
		    CheckSum -= 10; // Same as MOD 10, but faster
		}
	    }
	} else {
	    return(Validity);	// Invalid
	}
    }
    Validity = (CheckSum == 0) ? true : false; // Must sum to 0
  }
  return(Validity);
}


function check(){
    if (document.PaymentForm.cardtype.value=="NONE") alert("You must select a card type"); else
//    if (document.PaymentForm.expire2.value=="02" && (document.details.expire1.value=="01" ||
//        document.PaymentForm.expire1.value=="02")) alert("You must enter a valid expiry date"); else
    if (document.PaymentForm.cardname.value=="") alert("You must enter a name"); else
    if (document.PaymentForm.SecurityCode.value=="") alert("You must enter the Security Code"); else
    if (document.PaymentForm.cardno.value=="") alert("You must enter a card number"); else
    if (!ValidCard(document.PaymentForm.cardno.value)) alert("Invalid card number"); else
    document.PaymentForm.submit();
}

function ExpandTxt(In) {
  if (In == 1) {
    document.getElementById('txt1').style.display = '';
    document.getElementById('txt2').style.display = 'none';
    document.getElementById('txt3').style.display = 'none';
  }
  if (In == 2) {
    document.getElementById('txt1').style.display = 'none';
    document.getElementById('txt2').style.display = '';
    document.getElementById('txt3').style.display = 'none';
  }
  if (In == 3) {
    document.getElementById('txt1').style.display = 'none';
    document.getElementById('txt2').style.display = 'none';
    document.getElementById('txt3').style.display = '';
  }
}

最初由 aki 发布
这个看说明好像是建立网络验证的东西，老k给个可用的id，网页看不懂

最初由 KuNgBiM 发布
我也没有ID，那个与其说是网页代码，不如说是借用Delphi的语言而写成的XXXX...