The code is very messy. As to make it clearer and easier-to-understand I'd made some modifications.
Try this, I just removed the MARKER function as whenever a resource is started, the server reads everything so its not so needed (the onResourceStart event, I mean).
Btw, your mistake is that DRINKS function is below the eventHandler, which will mean, when the eventHandler is created, drinks function will not exist as it wasn't read yet, so easier would be:
theMarker3 = createMarker ( 497.24795532227,-75.805885314941,997.5578125, "cylinder", 1, 255, 105, 180, 170 )
setElementInterior ( theMarker3, 11 )
setElementInterior ( theMarker3, 11 )
function drinks(thePlayer)
outputChatBox("tits")
end
addEventHandler ( "onMarkerHit", theMarker3, drinks )
Be sure to use debugscript 3 in order to see any mistake (you'd have realized an error would have been shown