I 'll want to download somes files I put on the plugin onclick="GET(url of the file);" but the browser open the file, and I want download the file with the browser but not on the browser
Which kind of file is it? I had the same problem and at the end I solved it making a zip file. When the user clicked the button it promps to save the file.
if you want to be able to download all files regardless of filetype, you would need a small server script (php for example) that sends a correct http header for this case,