inventory gui? (reference image)

first of all i tried some scripts they did not work so i deleted them so i can not show any scripts.

reference: http://imgur.com/a/oqE9H

the top bar is a kind of hotbar the box under that is like a backpack

is there anyone that can help me with an inventory script that if you click like a weapon the weapon goes into your inventory

the weapon has clickdetector but can i do that with a localscript?

and how do i do something that if i have something in my inventory that i can drag into the hotbar i think

Slot1 = script.Parent.Frame.Slot1
player = game.Players.LocalPlayer
mouse = player:GetMouse()

Slot1.Position = mouse.Target

(i have not tried this)

but how do you get it that the icon keeps the slot you dragged it to?

if there is anything missing comment.