GUI positioning/resizing help?

I don't know if this would classify as "scripting" but I'm adjusting the properties of a GUI in a script so I guess I can ask here. This is a chunk from my script:

while wait() do
            wait(0.1)
            if keys["q"] and Tool.Val.Value > 0 then
                Tool.Val.Value = Tool.Val.Value - 10
                Tool.Handle.Meter.Frame.Size =  UDim2.new(Tool.Handle.Meter.Frame.Size - UDim2.new(0,0,0,5))
                Tool.Handle.Meter.Frame.Position = UDim2.new(Tool.Handle.Meter.Frame.Position - UDim2.new(0,0,0.5,0))   
            elseif keys["e"] and Tool.Val.Value < 200 then
                Tool.Val.Value = Tool.Val.Value + 10
                Tool.Handle.Meter.Frame.Size =  UDim2.new(Tool.Handle.Meter.Frame.Size + UDim2.new(0,0,0,5))
                Tool.Handle.Meter.Frame.Position = UDim2.new(Tool.Handle.Meter.Frame.Position + UDim2.new(0,0,0.5,0))
            end         
        end 
    end

Pressing the "q" key is supposed to make a bar-like GUI decrease and decrease a value, and pressing "e" would make the bar increase and increase a value. The value parts of the script work, but the GUI part doesn't seem to work at all. I think I may have messed up the numbers, I'm still confused on what each of the 4 numbers in a UDIM2 does.