Sir_RoyGbivv

Hey, in my mod i am trying to add a custom player inventory, i want it so when the player presses "e" the default inventory comes up but i also want a tab to come up that when pressed it brings up my inventory. All i need to know is how to add the tab and show the Gui when pressed on, i do not need to know how to add buttons and item slots all of that just how to display the gui when the tab is pressed on, thanks