Handyman question

I think this is one for the slides, Garnet.
Not sure I understand how to get the duck tape on, because of the way the slide works. If I am correct, I can put the duct tape on the part that slides into the grooved part?
 
Found a solution, finally! I have placed to two medium sized monster clips (used to hold stacks of papers) on each track, placing it where I want to the pull out keyboard shelf to "stick." I can slide the clips along the tracks, making it adjustable for when I want to type, or want to push the shelf inward a bit more, without it constantly sliding.
 
Found a solution, finally! I have placed to two medium sized monster clips (used to hold stacks of papers) on each track, placing it where I want to the pull out keyboard shelf to "stick." I can slide the clips along the tracks, making it adjustable for when I want to type, or want to push the shelf inward a bit more, without it constantly sliding.
Way to go Mrs MacGyver.