Record Range of Uniform Distribution

We consider a sequence of independent and identicaly distributed (iid) random variables with absolutely continuous distribution function F(x) and probability density function (pdf) f(x). Let Rnl be the largest observation after observing nth record and R(ns) be the smallest observation after observing the nth record. Then we say Wnr = Rnl - R(ns), n(GREATER THAN) I, as the nth record range. We will consider some distributional properties of Wnr when f(x) = 1 ,0 (LESS THAN OR EQUAL) x (LESS THAN OR EQUAL) 1.