code: function( command, param, force_selection )
          {
              // give selection to contenteditable element
              restoreSelection( node_contenteditable, popup_saved_selection );
              // tried to avoid forcing focus(), but ... - https://github.com/wysiwygjs/wysiwyg.js/issues/51
              node_contenteditable.focus();
              if( ! selectionInside(node_contenteditable, force_selection) ) // returns 'selection inside editor'
                  return false;
  
              // Buggy, call within 'try/catch'
              try {
                  if( document.queryCommandSupported && ! document.queryCommandSupported(command) )
                      return false;
                  return document.execCommand( command, false, param );
              }
              catch( e ) {
              }
              return false;
          }
docs: exec command https://developer.mozilla.org/en-US/docs/Web/API/document.execCommand http://www.quirksmode.org/dom/execCommand.html