Where to set Event Trigger?

Hi all,
I'm using LCD 8.0 making my forms. What I'm attempting to do is to create 2 buttons that adds and removes row from a table. I've search through the web and found a good example that uses the following command:

Table1.Row1.instanceManager.addInstance(1);
Table1.Row1.instanceManager.removeInstance(nNumSub);

Which I believe is exactly what I'm looking for, but my stupid problem is I can't find where do I put this piece of code. From the research I've done, it seems I need to edit the click event for it to execute the code on the click, but I'm pulling my hair out trying to find where to do it? Can any expert help me out? I've checked everywhere possible on all the tabs and still found nothing.

Daniel