Why isn't my midi working in mixcraft?

i got a yamaha psre223 a few days ago and i got a lightsnake midi-usb cord today everything seems to be working fine everything lights up it installed correctly on my computer and it shows up in the external midi devices in mixcraft. i am however having trouble recording it i set it up on the sound and on all midi channels and it doesn't work i hit record play what i want to but nothing is appearing and nothing is there on playback. so is there anything wrong with my cable or keyboard or is there something i'm missing about how midi works and how do i record from my keyboard into my computer then? thanks in advance :)