How to use Polaroid Studio Series Pro Slave on Nikon D3100?

I just recently bought this flash. Every time I want to use it, the flash make me have to test out the flash first. Is there anyway to make it so I don't have to do this?

Here is the link to the flash: http://www.amazon.com/...004DK8PGO/

If every time you test it, it works, then quit testing it and just use it.