Exclude FTP results from Google custom Search

Question

I did get my code to implement google custom search which is below:

<script> 
  (function() { 
    var cx = '007573243353096205708:4ydbnopnt9s'; 
    var gcse = document.createElement('script'); 
    gcse.type = 'text/javascript'; 
    gcse.async = true; 
    gcse.src = (document.location.protocol == 'https:' ? 'https:' : 'http:') + 
        '//www.google.com/cse/cse.js?cx=' + cx; 
    var s = document.getElementsByTagName('script')[0]; 
    s.parentNode.insertBefore(gcse, s); 
  })(); 
</script> 
<gcse:search></gcse:search> 

But this code and my public url shows me FTP results. When I try to exclude ftp results like ftp://www.mysite.com/* it excludes all results.

What should I do so that my search excludes FTP results.

I saw this link but could not understand where to put the code suggested https://productforums.google.com/forum/#!searchin/customsearch/ftp%7Csort:relevance/customsearch/CitHAOTAgS4/W79di_lOuS8J

Any help is appreciated.