Showing Entered webpage (site) after auto Login (Via http-post)

I used this link(sarangasl.blogspot.com) to make a login app to a website (via http-post). Now I need to open the logged in website in my app.

All is right until I use this code for displaying the logged in webpage:

   WebView wv = new WebView(getApplicationContext());
   wv.loadUrl("http://www.site.com/");
   this.setContentView(wv);

When I use the above code, this show login webpage to me, not the logged in version, even though my app logged into the website.

How can I display the logged site inside my app after my app logs in?