function [t, Wt] = BM_xing(n, scale)
% n co-ordinates of BM observed when it crosses levels scale*Z
% Zaeem Burq 23.3.06, Owen Jones 24.3.06
t = zeros(n+1, 1);
for i = 1:n
    t(i+1) = t(i) + xing;
end
Wt = [0; cumsum(sign(rand(n, 1) - 0.5))];
if nargin > 1
    t = scale^2.*t;
    Wt = scale.*Wt;
end