If you wish to modify the default ISL Pronto gadget for Google Sites, please download the default version from this link and save it to your computer:
http://pronto.isl.example.com/live/islpronto/public/google_gadget.xml?d=your_domain_name
Note: Replace "pronto.isl.example.com" with you ISL Conference Proxy server address and "your_domain_name" with the appropriate domain for which you are going to make modifications.
Edit the xml file and make the desired changes, then upload the gadget to your website. Once it is uploaded, add it to your site using the appropriate link to the modified gadget.