Running form

I have been running lately after my sundown. I run 2 to 3 times within a week. The knee pain comes back again because of my wrong running form. I landed with heels that injured my knee cap. http://www.newtonrunning.com/run-better/optimal-running-form I need to change my running form but to change it, I need to see me running. Like if you are doing aerobic or any kind of dancing, normally the room has mirror so you can see whether you are following the instructor correctly and most importantly is your posture.