function expected instead of nil

[Rahon]

Hello,

i run into following issue:

user:/AddOns/FooAddon/FooAddon.lua:5: function expected instead of nil
        stack traceback:
	user:/AddOns/FooAddon/FooAddon.lua:5: in function '(main chunk)'

when im trying to run this code:

ADDON_NAME = "Test"

EVENT_MANAGER: RegisterForEvent(ADDON_NAME,EVENT_MOUNTED_STATE_CHANGED, IsOnMount())
  -- d(IsMounted("player"))
  -- d(onMount)
 
 local function IsOnMount(event, onMount)
   
 if onMount == IsMounted("player")
   then d("Mounting")
   else d("Unmounting")
   
     
 end

I'm guessing that it has something to do with "IsOnMount()" not receiving and/or the EVENT_MANAGER not giving away its variables - in this case the EventID and the Boolean value.

This is my first experience in coding in lua, so im glad for any help I can get.

cheers