Hello.... I am frustrated and need help!

I needed an external monitor for my new office and found a 20" Cinema Display for what I thought was a great deal. It did not come with a power adapter and found out after it arrived that this is the model that was powered by the G4 and G5 computers. None of the small Apple Indy stores in my area would help me.. so I turned to the internet and found that I could purchase an Apple A1096 adapter (power block they call it) to power it. When I plug everything in.. I am still not showing any power.. is this because I do not yet have the DVI to Mini Display Port adapter?

Does anyone know what exactly I need to get this thing to work? For what I've already spent I could have bought one heck of a brand new one with a TV tuner in it.. but now that I've gotten this far.. I'd like to get it to work instead of collecting dust in my office floor.