How can i stop my sunroof leeking? Renault scenic X reg?

How can i stop my Renault Scenic X Reg (2001) front sunroof leeking. the water runs down the inside of the car above the doors each side and sometimes in really bad weather the water drips down through the electric sunroof overhead controls. We have tried seek and seal along the top of the windscreen and putting grease along the roof rails