I recently came to my attention that there are not really any good sliding door child locks, either that or our 2 year old is more naughty than others. All we have tried either would damage the door, look incredibly ugly, or was easily outsmarted by our toddler. So I came up with my own child lock, which is discrete, child proof, and has minimal impact on the door.

Warnings:
1. I am not responsible for any damage you inflict on your door, surrounding area, or yourself while following this instructable.
2. This works because most doors have a space between the top of the door and the frame. This allows the D-links to fold and unfold on themselves as the door opens and closes. If your door is not made this way this may not work, so check before you drill any holes.

Step 1: Materials and Costs

Materials:
Package of D-rings from Wal-Mart- $1.79
Package of J-hooks from Wal-Mart- $1.29
Dowel from Wal-Mart (I chose the thickness that was big enough it wouldn't buckle)- $2.49

Tools:
Drill
Drill bit for pilot holes
Phillips bit head

Step 2: Prepare the Dowel

I measured the space on the inside between the door and the frame with the door open, and then again with the door open the maximum amount that I wanted our child to be able to open it (which ended up being ~2inches smaller than the width of his head).

I then cut the dowel to that length with a hand saw.

Next I drilled pilot holes for the j-hooks. I did them about 8inches from each side of the dowel.

Once the holes are drilled screw the j-hooks in by hand. Make sure that at the end they face the same direction.

Step 3: Door Frame

The beauty of this method was the only holes in the door are 2 little pilot holes in the top of the door track. I held the dowel with the j-hooks up to the track, as far as it would go away from the door and marked with a pencil where I wanted the J-hooks.

Next I held the D-ring up with the ring hanging along the penciled line, and the part with the hole facing toward the door. Then mark with the pencil inside of the hole on the door track.

Next drill a pilot hole in the door track for each d-ring. Then install the d-rings.