the seal 48 as depicted in fig2 the slot 30 includes a drain pipe 66 leading from the lowest portion of the slot 30 to remove excess fluid preferably the drain pipe 66 is fashioned from a clear plastic tubing for example so that the collection of fluid within the drain pipe 66 can be observed if such fluid is observed then it is most likely that the seal 48 should be replaced by removing strap 50 and repositioning a new seal 48 for retention by strap 50 and screws 51 in order to hold the panel 40 tightly in position a hook member 68 projects from the mid point along the bottom of the panel 40 and extends into a slot or passage near the bottom of the opening 22 hook member 68 thus projects through slot 72 the hook member 68 is positioned on the outside of the panel 40 and extends through a separate slot 72 in the side wall of the tub construction there the hook member 68 is engaged by a gripping member 76 which may be motorized to engage the hook member 68 and tightly draw the hook member 68 downward in direction of the arrow in fig2 this retains panel 40 tightly in sealing engagement with the slot 30 motor.