void setActive(String name){
        Sheet a=null;
        for(Sheet s:sheets){
            if(s.getName().equals(name)){
                a=s;
                break;
            }
        }
        if(a==null) return ;
        switch(viewType){
            case VIEWTYPE_TABS:{
                JTabbedPane tabs=(JTabbedPane)container;
                tabs.setSelectedComponent(a);
            }break;
            case VIEWTYPE_MDI:{
                JDesktopPane mdi=(JDesktopPane)container;
                ((JInternalFrame)a.getParent()).restoreSubcomponentFocus();
            }break;
        }
    }