error: 'Sample' undefined near line 1, column 1

Question

function x = E(Landa,N)
y = rand(1,N)
for i = 1:N
x(1,i)= -(ln(1-y(1,i)))/Landa
end
end

Sample = E(2 , 100000)
ExpRange= linspace ( min(Sample), max(Sample) , 50 )