It seems like you are expecting this piece:

-script=>{-language=>'JavaScript', -src=>'row.js'}
[download]

To do something other than what it does.

The parameter above in start_html generates html in the header that should look something like:

   <script language='JavaScript' src='row.js' />
[download]

Which a browser will interpret by requesting the file 'row.js' from the server and inserting it in its internal representation of the document.

This should work, as long as row.js is in the same directory as the CGI script being called. If you want to include a file containing JS markup and have it all returned as on chunk to the browser, have a look at using HTML::Template, or read the file yourself and print it between <script> tags.