var prevDisplay='';
function showHelp(val)
{
    if(prevDisplay!='')
    {
        element = document.getElementById(prevDisplay);
        if(element!=null)
        {
            element.style.display='none';
        }
    }
        
    if(val != '')
    {
        prevDisplay =val;
        element = document.getElementById(val);
        if(element!=null)
        {
            element.style.display='';
        }
    }
}   




function validateCreditCard(s) 
{
    // remove non-numerics
    var v = "0123456789";
    var w = "";
    for (i=0; i < s.length; i++) 
    {
    x = s.charAt(i);
    if (v.indexOf(x,0) != -1)
    w += x;
    }
    
    // validate number
    j = w.length / 2;
    if (j < 6.5 || j > 8 || j == 7) return false;
    k = Math.floor(j);
    m = Math.ceil(j) - k;
    c = 0;
    for (i=0; i<k; i++) 
    {
    a = w.charAt(i*2+m) * 2;
    c += a > 9 ? Math.floor(a/10 + a%10) : a;
    }
    for (i=0; i<k+m; i++) c += w.charAt(i*2+1-m) * 1;
    return (c%10 == 0);
}



        function jfToggleDiv(val)
        {
            element = document.getElementById(val);
		    if(element.style.display=='')
		    {
			    element.style.display='none';
			  
		    }else
		    {
			    element.style.display='';			    
		    }
        }


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
}