anchor.diff:                      accept: ['marker', 'new-marker'],
                       hoverclass: 'hover',
                       onDrop: moveMarker })
  +                    registerHoverTip(item, "Click the grid cell to add an activity for all subjects")
               }
               );
   
  
positive.code:             executeUpdateDetails(input)
          })
      })
  }
  
  function updateAddActivityButton() {
  
negative.code: .palette div#delete-drop.hover {
      background-color: #f99;
      cursor: pointer;
  }
  
  .counter.hover {
      background-color: #f99;
  }
  
  .palette .tip {
  