Re: case sensitivity:
.rows != .Rows
.cols != .Cols
Re: <button type=button>... Well, I learned something new today. But if you uncomment those ".type = 'button'" lines, IE doesn't work anymore.
Also, onclick takes functions, not the returned value of a function call... .onclick = HeightDecrease; rather than .onclick = HeightDecrease();
(I think onclick can take strings too, but I'm not sure.)