title: addJavascriptInterface doesnt return a string value in Android
body: <p>I'm using following code to extract a string variable in my JavaScript file in Android:</p>
  
  <p>This is my JavaScript file:</p>
  
  <pre><code>&lt;script language="javascript"&gt;
  
  //EDIT:
  clsVariable = "vikrant";
  
  function refuseClick(){
  clsVariable = "vikrant";
  refuse.performClick();
  document.getElementById("no").value = "Refuse";
  }
  
  &lt;/script&gt;
  
  &lt;button type="button" id="no" onClick="refuseClick();"&gt;Je refuse&lt;/button&gt;
  
  &lt;/div&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>In my Android class I'm writing following method on a button click. This button click event I'm calling from JavaScript file:</p>
  
  <pre><code>    refuse.setOnClickListener(new View.OnClickListener() {
  
    @Override
    public void onClick(View v) {
        Log.v(LOG_TAG, "variable=" + clsVariable);  //This shows me null
   }
   });
   wbvw = (WebView) findViewById (R.id.webvw);
  
   wbvw.setWebViewClient(new HelloWebViewClient());
      wbvw.getSettings().setJavaScriptEnabled(true);
  
      WebSettings ws = wbvw.getSettings();
      ws.setJavaScriptEnabled(true);
      wbvw.addJavascriptInterface(clsVariable, "clsVariable");
      wbvw.loadUrl("http://www.sbc.co.in/projects/AndroidTest.html");
  }
  </code></pre>
  
  <p>I'm new to this platform as well as writing JavaScript.</p>
  
  <p>What is it that I'm doing wrong?</p>