[Mod request] Make inventory come up by clicking the scroll wheel

I just got Minecraft several days ago and one thing that has been annoying me is that you can't set the inventory button to be the scroll wheel click. Technically you can, but when you do they inventory comes up bit you can't get rid of it with the scroll wheel button, you have to click escape. I don't know how hard this would be to implement, but I would appreciate it if someone with the know-how took a crack at it. Thanks