Uncaught TypeError: Cannot set property 'inner

I am making a barcode scanning app using phonegap-1.4.1 for android. I need to define a n array code[] which can store all the barcode text scanned and i need to define a variable k which act as a counter which get incremented by 1 after every scan so that I can store detail in code[k]. So here is my previous javascript file where i have defined an array and an variable counter.

     localStorage["counter"]=0;
     var code = new Array(100);
     localStorage.setItem("code", JSON.stringify(code));

and here is my another js file where i am calling the stored array and printing the value stored in that array as "id". myvalue1 is the barcode text obtained from the scan.

   var barcodeVal = localStorage.getItem("myvalue1");
   var test2 = localStorage.getItem("code");
   code = JSON.parse(test2);
   var k = parseInt(localStorage.getItem("counter"));
   code[k] = "code[k]";
   document.getElementById(code[k]).innerHTML = barcodeVal;
   k = k + 1;
   localStorage["counter"]=k;
   localStorage.setItem("code", JSON.stringify(code));

I am calling the barcode scan function again and again. Thats why I am using an array for storing the data of the Barcode scanned.Here is my scan js file as well which gives the value of myvalue1

 <script type="text/javascript">
  var scanCode = function () {
      window.plugins.barcodeScanner.scan(
          function (result) {

               alert("Scanned Code: " + result.text + ". Format: " + result.format + ". Cancelled: " + result.cancelled);
              localStorage.setItem("myvalue1", result.text);
              window.location.href = 'page5.html';

          }, function (error) {
              alert("Scan failed: " + error);
       });
  }

I am getting the error as Uncaught TypeError: Cannot set property 'innerHTML' of null. I am new to phonegap and coding . Anyone please help me out with the issue. Thanks in advance.

You don't need to keep track of variable k. You simple manage your all barcode values using below script.

Please check below jsFiddle...Run it twice you can see difference.

JSFiddle

<script>
function SaveDataToLocalStorage(barcodeValue)
{

    var oldItems = JSON.parse(localStorage.getItem('barcodes')) || [];
    var newItem = {
        'barcode': barcodeValue
    };
    oldItems.push(newItem);
    localStorage.setItem('barcodes', JSON.stringify(oldItems));

}
SaveDataToLocalStorage("123456879FFGG");
</script>