@iaswariya: What I see from Ashish's answer, your problem is the value that has been set in database table qa_options, see for 'site_url'. There should be the correct URL. In other words, if your website runs with "www.yourwebsite.com" the site_url should have exactly this value. Then it should work.
You should correct this to prevent problems with other plugins as well.
Also do a rewrite of your URLs using .htaccess. All URLs should be rewritten to "www."-URLs.