Hi. I am a beginner trying to connect straight lines. After selecting the pencil tool, I click on the image where I want my line to start. I then hold down the shift key and drag my finger on the trackpad to make the line go to the endpoint. While still holding the shift key, I single click as well as double click to have my line drawn to the endpoint but it does not draw the line. It moves the cursor to the intended endpoint. I have tried one and two finger clicking on the right and left sides of my trackpad and have tried every setting on the trackpad that I know of. I have also tried using control to make a right click. I am using MacBook Pro OS X Lion 10.7.5 on Safari 6.0. Any help is appreciated.