How do you check the oil in a suzuki quad runner 250?

To check the oil on a suzuki quadrunner 250 you have to look between the back fender and the right rear wheel (If you r standing in front of the back of it) there is this little glass circle on the motor just clean it off with your finger and if you will see the oil lever im not sure or not oif the oil is soposed to be over the glass or half way or not im trying to find that out my self if you know