Yet another question (yep, I am really new <img src="smileys/smiley36.gif" border="0" align="middle" /> )
in the formel (or script, whatever it is called) it says 'grid' and when I am trying to replicate the line it tells me to define 'grid', what should I type? haha
floor(MouseY/global('grid'))*global('grid')+global('grid')/2
global('[text]') means the global variable [text]. In this case, it's trying to make a new global variable named grid as it does not exist yet in your project. Global variables stay at their set value between all layouts/levels so they are basically named values. However, you can use events to change the value if you need to.
In this case, you can replace the whole global('grid') section with a number size that you want for your grid size, or go ahead and define it.
Hope that helps!