// reusable even handler code used to parse query string on page load.
function addEvent(obj, evType, fn){ 
 if (obj.addEventListener){ 
    obj.addEventListener(evType, fn, true); 
    return true; 
 } else if (obj.attachEvent){ 
    var r = obj.attachEvent("on"+evType, fn); 
    return r; 
 } else { 
    return false; 
 } 
} 

// QueryString 
// Call function by x = querystring("variable") returns variable=x 
function QueryString(key) 
{
QueryString_parse(); 
var value = null; 
for (var i=0;i<QueryString.keys.length;i++) 
{ 
if (QueryString.keys[i]==key) 
{ 
value = QueryString.values[i]; 
break; 
} 
} 
return value; 
} 


function QueryString_parse() 
{ 
QueryString.keys = new Array(); 
QueryString.values = new Array();

var query = window.location.search.substring(1); 
var pairs = query.split("&"); 

for (var i=0;i<pairs.length;i++) 
{ 
var pos = pairs[i].indexOf('='); 
if (pos >= 0) 
{ 
var argname = pairs[i].substring(0,pos); 
var value = pairs[i].substring(pos+1); 
QueryString.keys[QueryString.keys.length] = argname; 
QueryString.values[QueryString.values.length] = value; 
} 
} 
} 


function IsNumeric(sText)
{
   var ValidChars = "0123456789";
   var IsNumber=true;
   var Char;

 
   for (i = 0; i < sText.length && IsNumber == true; i++) 
      { 
      Char = sText.charAt(i); 
      if (ValidChars.indexOf(Char) == -1) 
         {
         IsNumber = false;
         }
      }
   return IsNumber;
   
   }
   
function MaxLength(sText, iMax)
{
   var IsValid=true;
   
   
      if (sText.length > iMax) 
         {
         IsValid = false;
         }
      
   return IsValid;
   
}

function RangeLimit(sText, iMin, iMax)
{
   var IsValid=false;
   
   
      if (sText.length >= iMin && sText.length <= iMax) 
         {
         IsValid = true;
         }
      
   return IsValid;
   
}

function Mod10(ccNumb) {  // v2.0
var valid = "0123456789"  // Valid digits in a credit card number
var len = ccNumb.length;  // The length of the submitted cc number
var iCCN = parseInt(ccNumb);  // integer of ccNumb
var sCCN = ccNumb.toString();  // string of ccNumb
sCCN = sCCN.replace (/^\s+|\s+$/g,'');  // strip spaces
var iTotal = 0;  // integer total set at zero
var bNum = true;  // by default assume it is a number
var bResult = false;  // by default assume it is NOT a valid cc
var temp;  // temp variable for parsing string
var calc;  // used for calculation of each digit

// Determine if the ccNumb is in fact all numbers
for (var j=0; j<len; j++) {
  temp = "" + sCCN.substring(j, j+1);
  if (valid.indexOf(temp) == "-1"){bNum = false;}
}

// if it is NOT a number, you can either alert to the fact, or just pass a failure
if(!bNum){
  /*alert("Not a Number");*/bResult = false;
}

// Determine if it is the proper length 
if((len == 0)&&(bResult)){  // nothing, field is blank AND passed above # check
  bResult = false;
} else{  // ccNumb is a number and the proper length - let's see if it is a valid card number
  if(len >= 15){  // 15 or 16 for Amex or V/MC
    for(var i=len;i>0;i--){  // LOOP throught the digits of the card
      calc = parseInt(iCCN) % 10;  // right most digit
      calc = parseInt(calc);  // assure it is an integer
      iTotal += calc;  // running total of the card number as we loop - Do Nothing to first digit
      i--;  // decrement the count - move to the next digit in the card
      iCCN = iCCN / 10;                               // subtracts right most digit from ccNumb
      calc = parseInt(iCCN) % 10 ;    // NEXT right most digit
      calc = calc *2;                                 // multiply the digit by two
      // Instead of some screwy method of converting 16 to a string and then parsing 1 and 6 and then adding them to make 7,
      // I use a simple switch statement to change the value of calc2 to 7 if 16 is the multiple.
      switch(calc){
        case 10: calc = 1; break;       //5*2=10 & 1+0 = 1
        case 12: calc = 3; break;       //6*2=12 & 1+2 = 3
        case 14: calc = 5; break;       //7*2=14 & 1+4 = 5
        case 16: calc = 7; break;       //8*2=16 & 1+6 = 7
        case 18: calc = 9; break;       //9*2=18 & 1+8 = 9
        default: calc = calc;           //4*2= 8 &   8 = 8  -same for all lower numbers
      }                                               
    iCCN = iCCN / 10;  // subtracts right most digit from ccNum
    iTotal += calc;  // running total of the card number as we loop
  }  // END OF LOOP
  if ((iTotal%10)==0){  // check to see if the sum Mod 10 is zero
    bResult = true;  // This IS (or could be) a valid credit card number.
  } else {
    bResult = false;  // This could NOT be a valid credit card number
    }
  }
}
// change alert to on-page display or other indication as needed.
//if(bResult) {
//  alert("This IS a valid Credit Card Number!");
//}
//if(!bResult){
  //alert("This is NOT a valid Credit Card Number!");
//}
  return bResult; // Return the results
}

function GoToUrl(url) {
        //alert("click works");
        document.location.href = url;
    }