title: How to show android alert dialog in Webview?
body: <p>I am Developing an app with webview but I don't know how to enable JavaScript to show alert dialog in webview.</p>
  
  <p>I ever tried this one but it's isn't work for me.
  firstly,I made webview and websettings object
  then set following parameters.</p>
  
  <pre><code>    webSettings.setJavaScriptEnabled(true);
  
      webSettings.setBuiltInZoomControls(true);
  
      mWebView.requestFocusFromTouch();
  </code></pre>