How would I make a level up Gui Bar using Int Values?

Let's say a 100x20 frame would represent your XP bar. Inside of this XP bar, you would input another frame and preferably name it 'XP.' After this, you should size 'XP' to {0,0},{1,0}. I would put the IntVal inside of 'XP.' Put a script inside of XP with the following code:

while true do
	wait()
	script.Parent.Size.X.Offset = script.Parent.IntValue.Value
end

This is a super simple, maybe a level 1 XP bar, because I can't really type up a huge one on this site, but this will get you started.