I do not know how old my garage door is; however I have been in the house for 8 years and it was here before me. When I open the garage door it stops about every foot or so. I literally push the button atleast 8-15 times. When I close the door it stops about at the same place but starts to go back up automatically. I downloaded the Genie ScrewDrive manual Series IS, ISL, IC, and H and looked at the setting where there are suppose to be two screws on the back to adjust the close and open; however there are two places for screw, but no screws. Have any ideas?