<script src = 'lib/DesktopApp.js'> <!-- or wherever you put it --></script>

<script>
  DesktopApp.create({         // tell the desktop that this window contains an application
    docs: {                   // this application knows how to use documents
      'text/html': {          // we can process text/html
        new: function(cb) {   // provide content for a a new doc of this type
          cb(null,'');       // the new content is an empty string
        },
        open: function(content,cb) {      // open a document
          $('#editor').html(content);
          cb(null,'OK');
        },
        save: function(cb) {              // save a document
          cb(null, $('#editor').html());
        }
      },
      'text/plain': {         // we can also process text/plain
        catch: 'text/*',      // ... and we'll treat any text file as text/plain
        new: function(cb) {   
          cb(null,'');         
        },
        open: function(content,cb) {        // open a document
          $('#editor').text(content);
          cb(null,'OK');
        },
        save: function(cb) {                // save a document
          cb(null, $('#editor').text());
        }
      }
    }
  })
</script>