On Show add
TestForEnable = 0;
TestForDisable = 0;
And change your functions like so.
if e_Modifiers.ctrl and e_Key == 70 then --Press ctrl + "F"
TestForEnable = TestForEnable + 1;
elseif e_Key == 85 then --letter "U"
TestForEnable = TestForEnable + 1;
elseif e_Key == 67 then --letter "C"
TestForEnable = TestForEnable + 1;
elseif e_Key == 75 then --letter "K"
TestForEnable = TestForEnable+ 1;
if(TestForEnable == 4)then
xButton.SetEnabled("xButton1", true);
-- Reset TestForEnable
TestForEnable = 0;
end
end
This means the user can't just press K and D to enable and disable the buttons like you had it before.
and to make it a little more complex you could also create a timer what resets TestForEnable and disabled
the timer after the modifer as been enabled.