i believe it's spelt 'cartridge' my good man, sorry had a good laugh at cartilage.. but, if you can just pop it out and look thats the easiest, sometimes if you put in a new set the computer will monitor it though
Some printer driver installations have ink level monitor software, so you can click on a button and have a thermometer-like gauge of how full your cartridges are. Others have no warning at all and the first sign you need ink is a lousy print!
Tom