title: How to let user choose output file name in writecsv
body: <p>Any idea how to let the user choose the filename to save using this function ?</p>
  
  <pre><code>write.csv(tweets, file = "newfile.csv",
            row.names = TRUE, sep = ',', 
            col.names = TRUE)
  </code></pre>
  
  <p>Something like how we use the save as function and then a browser option appears.</p>