Report Formula

Hi

I have 4 parameters . From Date , To Date , Product , UserSign.

From Date & To Date to be mandatory. I am using Owor , Wor1 tables.

I want if user Enters From Date & To Date only then records get filtered only on date Basis.

if user enters Date & Product then records get filtered only on date Basis & Product

if user enters Date & UserSign then records get filtered only on date Basis & UserSign

if user enters Date , Product , UserSign then records get filtered on Date Basis , UserSign , Product.

Thanks