Randomize Double Number in VB .NET 2005

[ichee]

Hi all,
Is there any of u know how to randomize a double number in VB then use it as decimal type?
I've try it many times, but unfortunately i'm still failed. I used this :

private sub Init()
dim objRandom as System.Random
dim v(5,20), w(5) as decimal
dim Rndv(5,20), Rndw(5) as double
dim i,j as integer

for j = 0 to 4
for i = 0 to 19
Rndv(j,i)=objRandom.nextdouble()
v(j,i)=Rndv(j,i)-0.5
next i
Rndw(j)=objRandom.nextdouble()
w(j0=Rndw(j)-0.5
next j

end sub

thanks