function htmlbox_undo_redo_manager(repeat){var r=false;var d=[];var p=0;this.d=function(){return d;}this.add=function(o){if(d[p-1]==o)return false;d[p]=o;p++;d=d.slice(0,p);};this.can_redo=function(){if(p>=d.length){return false;}return true;};this.can_undo=function(){if(p<1){return false;}return true;};this.clear=function(){d=[];p=0;};this.undo=function(){if(p<1){return false;}p--;return d[p-1];};this.redo=function(){if(p>=d.length){return false;}p++;return d[p-1];};}