Midi connecting problems: using Logic Express 9 with MBox 2 interface and a Mac OSX 10.6.8

I have a Mac OSX and I use Logic Express 9 on it. I also use an MBox 2 digidesign. Im having trouble connecting midi and getting it to work from my Roland Keyboard Midi, to the back of my Mbox 2 Midi. Its just not working at all. Does anyone know how to make Midi work with the Mbox 2 using Logic Express 9 on my OSX 10.6.8