Update how-to-exclude-wia-sources-in-the-source-list.md

Author: ztyyLV

faq/how-to-exclude-wia-sources-in-the-source-list.md

@@ -15,12 +15,23 @@ permalink: /faq/how-to-exclude-wia-sources-in-the-source-list.html
 
 > Applicable to Windows only
 
-
+There are two ways to achieve this:
 
 * Set [IfUseTwainDSM]({{site.info}}api/WebTwain_Acquire.html#ifusetwaindsm) to `true`
 
 ``` javascript
 DWObject.IfUseTwainDSM = true;
 ```
 
+* Filter sources before listing them
+
+``` javascript
+var sources = DWObject.GetSourceNames();
+for (var i = 0; i < sources.length; i++) {
+    if (sources[i].toLowerCase().indexOf('wia') != -1) {
+        sources.splice(i, 1);
+    }
+}
+```
+
 If you are still having issues with a device, please feel free to [contact us](https://www.dynamsoft.com/company/contact/) via email, live chat, or phone call.