Player hit the marker

[PezFenix2016]

Hello, this is just a little question, how can I know if a player already hit a marker? I mean, I created a marker, then executed certain functions once the player hit the marker, but it's executing those functions again when the player hit the marker again. How can I make a restriction for that? I just want it works only once (only when the player hit the marker for the first time).

Someone told me to use tables so I can get the players' names on it, then make a restriction with those names, but I don't know how to start. can someone give me a hand with useful functions that I can use to make it works? thanks for taking your time on reviewing my topic. 

[AE.]

you don't have  to make tables :L

just setElementData for the player who enter the marker
and when he hit it 
if getElementData
if its true then retrurn end
and if its false continue the function

[Thrzu]

local enteredPlayers = {}
local myMarker = createMarker(0, 0, 2.5, "cylinder", 2.0, 255, 0, 0, 150)

function MarkerHit( hitElement, matchingDimension )
    if getElementType( hitElement ) == "player" and matchingDimension then
	    if (not enteredPlayers[hitElement]) then
		    enteredPlayers[hitElement] = true
			outputChatBox(getPlayerName(hitElement).." entered the marker for the first time.", hitElement, 0, 255, 0)
		else
		    outputChatBox(getPlayerName(hitElement).." entered the marker before.", hitElement, 255, 0, 0)
		end
	end
end
addEventHandler( "onMarkerHit", myMarker, MarkerHit )