title: Finding the web address of a Javascript link
body: <p>I am using <code>RCurl</code> in R to try and download data from a website, but I'm having trouble finding out what URL to use.  Here is the site: </p>
  
  <p><a href="http://www.invescopowershares.com/products/holdings.aspx?ticker=PGX" rel="nofollow noreferrer">http://www.invescopowershares.com/products/holdings.aspx?ticker=PGX</a></p>
  
  <p>See how in the upper right, above the displayed sheet, there's a link to download the data as a <code>.csv</code> file?  I was wondering if there was a way to find a regular HTTP address for that <code>.csv</code> file, because <code>RCurl</code> can't handle the Javascript commands. </p>