Thanks Richard I've now got this working.

This is my fist time with any scripting language and I was wondering if you could give me some assistance with your example.

I tried your example as above but it was failing with an error of $skey not defined. I am reading the manual and it goes on to say the first reference to $GlobalVariable will become global visible I took this to mean that because I'm not using $skey anywhere eles in my script. I would be able to simply copy your example into my script as is. This is what I tried to do and this is where it failed.

If I put the $skey "" at the start of my script it then works. I decided against this approach and instead went for Dim $skey which also worked.

Secondly, what is the purpose of $sNul? I'm confused because there's no reference to this variable so why use?

Thanks