API IsModifierKeyDown

Returns true if a modifier key is currently pressed down.
isDown = IsModifierKeyDown() <- IsControlKeyDown() <- IsLeftControlKeyDown()
 <- IsRightControlKeyDown()
 <- IsShiftKeyDown() <- IsLeftShiftKeyDown()
 <- IsRightShiftKeyDown()
 <- IsAltKeyDown() <- IsLeftAltKeyDown()
 <- IsRightAltKeyDown()
==Returns==
:;isDown: - True if the specified modifier key is pressed down.
==Details==
==Example==
Prints if the left-ctrl and left-shift modifiers are pressed down.
local function OnEvent(self, event, ...)
	if IsLeftControlKeyDown() and IsLeftShiftKeyDown() then
		print("hello")
	end
end
local f = CreateFrame("Frame")
f:RegisterEvent("MODIFIER_STATE_CHANGED")
f:SetScript("OnEvent", OnEvent)