+Lightbox.prototype.getCBIndex = function(cb) {
+       if (!this.cbIndex) {
+               // build checkbox index
+               this.cbIndex = [];
+               var i, node, c;
+               var nodes = this.grid.childNodes;
+               for (i=0 ; i<nodes.length ; i++) {
+                       node = nodes[i];
+                       if (node.nodeName === 'SPAN') {
+                               c = node.getElementsByTagName('input')[0];
+                               c.index = this.cbIndex.length;
+                               this.cbIndex[this.cbIndex.length] = c;
+                       }
+               }
+       }
+       return cb.index;
+};
+
+Lightbox.prototype.selectCBRange = function(evt) {
+       var target = getTargetedObject(evt);
+       evt = getEventObject(evt);
+       var shift = evt.shiftKey;
+       if (shift && this.lastCBChecked) {
+               var from = this.getCBIndex(this.lastCBChecked);
+               var to = this.getCBIndex(target);
+               var start = Math.min(from, to);
+               var stop = Math.max(from, to);
+               var i;
+               for (i=start ; i<stop ; i++ ) {
+                       this.cbIndex[i].setAttribute('checked', 'checked');
+               }
+       }
+       else if (target.checked) {
+               this.lastCBChecked = target;
+       }
+       else {
+               this.lastCBChecked = undefined;
+       }
+};
+
+