title: PHP check if visitor liked my FB page
body: <p>I am making a website, where I ll be keeping a download button, the download will be only available when the visitor will click the like my FB Fanpage. This should detect whether the user already liked it or its the first time.</p>
  
  <p>I googled a lot, but didn't found exact solution to my query.</p>
  
  <p>Can anyone help me?</p>