I use tab for open inventory button, but it's always bothered me that you can't use the same button to close it; instead you have to use Esc or the X button in the corner of the inventory.   Here is some code so you can have a button that opens the inventory, and the same button closes it.   Put it in initPlayerLocal.sqf or similar.   Enjoy   player addEventHandler ["InventoryOpened",{     _this spawn {         waitUntil {             not isNull (findDisplay 602)         };         INVCLOSED = (findDisplay 602) displayAddEventHandler ["keydown", {             if ((_this select 1) in (actionKeys "gear")) then {                 (findDisplay 602) displayRemoveEventHandler ["keydown",INVCLOSED];                 closeDialog 0             }         }]     } }]