Making selectables with columns?

[PK8]

Heya, I can't figure out for the life of me how to make selectables which contains 2 or more columns (like the item windows). Could someone teach me how to pull it off? :P

Edit: What the heck? I can't believe I figured it out... also, I can't believe I had to add a line to make it column based. o______o

For anyone interested, just add
@column_max = value into the initialize method of your selectable window. Topic resolved.