You most likely have laminated safety glass since it's only cracked, which is easy to replace. Get the dimensions and any glass shop can cut it for you. Tempered glass is cut then tempered. When it breaks, it will be into lots of little pieces with no sharp edges.
The laminated safety glass is the same stuff that your windshield on your car is made out of and the side windows are tempered glass. Google tempered and laminated glass for a better description.
We replaced the center window on Hobo for ~$20 with clear 1/4" laminated safety glass.