code: function( buttonName, commandName, dialogFile )
  		{
  			editor.addCommand( commandName, new CKEDITOR.dialogCommand( commandName ) );
  
  			editor.ui.addButton( buttonName,
  				{
  					label : lang.common[ buttonName.charAt(0).toLowerCase() + buttonName.slice(1) ],
  					command : commandName
  				});
  			CKEDITOR.dialog.add( commandName, dialogFile );
  		}
docs: All buttons use the same code to register. So, to avoid duplications, let's use this tool function.