docs: fixed wrong code snippet for retrieving original image

Author: Tom-Dynamsoft

programming/javascript/user-guide/index.md

@@ -504,15 +504,23 @@ await cvRouter.startCapturing("ReadSingleBarcode");
 Please be aware that it is necessary to update the `CapturedResultReceiver` object to obtain the original image. For instance:
 
 ```javascript
-const EnumCRIT = Dynamsoft.Core.EnumCapturedResultItemType;
-resultReceiver.onDecodedBarcodesReceived = (result) => {
-  if (result.barcodeResultItems?.length) {
-    // Use a filter to get the image on which barcodes are found.
-    let image = result.items.filter(
-      item => item.type === EnumCRIT.CRIT_ORIGINAL_IMAGE
-    )[0].imageData;
-  }
-};
+const EnumCRIT = Dynamsoft.Core.EnumCapturedResultItemType; // Enum for captured result item types.
+// Create a result receiver to handle the results.
+cvRouter.addResultReceiver({
+  // This function is called when any capture result is received.
+  onCapturedResultReceived: (result) => {
+    //Check for barcode results
+    let barcodeResultItems = result.items.filter((item) => item.type === EnumCRIT.CRIT_BARCODE);
+    if (barcodeResultItems.length > 0) {
+      let image = result.items.filter((item) => item.type === EnumCRIT.CRIT_ORIGINAL_IMAGE)[0]?.imageData; // Retrieve the original image.
+      if (image) document.body.appendChild(image.toCanvas()); // Append the image to DOM.
+      for (let item of barcodeResultItems) {
+        // Print each barcode result to the console.
+        console.log(`Barcode: ${item.text}, Format: ${item.formatString}`);
+      }
+    }
+  },
+});
 ```
 
 #### 1.3. Change reading frequency to save power