NEED HELP WITH TERRAIN ID

I need to make a certain tile trigger a common event, so I used store terrain ID and gave the tile the forest terrain ID, but when ever I go onto the forest tile it still says that I am on the plains terrain. I have a parallel event that stores the terrain ID where the hero is standing. Can someone tell me what I am doing wrong?

I did exactly that. For some reason it doesn't change ID when I move onto forest tile.

Edit: I had the variables in the wrong place for the coordinates. Thanks Darken for your help.