gridList error

[Potato_Tomato420]

I'm currently busy scripting a truckerjob for my server but i have a problem.
When the players hits the job marker and doesn't choose a skin the debug says:

WARNING: [gameplay]\SAFtrucker\mainServer.lua:11: Expected number, got non-convertible string. This warning may be an error in future versions.

I know what the errors means but i have no idea how to solve it.

GridList:
 

	truckerSkinGL = guiCreateGridList(0, 100, 300, 115, false, truckerWindow)
	guiGridListAddColumn(truckerSkinGL, "ID:", 0.2)
	guiGridListAddColumn(truckerSkinGL, "Skin Name:", 0.7)
	for i = 1, 2 do
		guiGridListAddRow(truckerSkinGL)
	end
	guiGridListSetItemText(truckerSkinGL, 0, 1, "132", false, false)
	guiGridListSetItemText(truckerSkinGL, 0, 2, "Male Trucker", false, false)
	guiGridListSetItemText(truckerSkinGL, 1, 1, "198", false, false)
	guiGridListSetItemText(truckerSkinGL, 1, 2, "Female Trucker", false, false)

 

Function:
 

function takeTruckerJob(button, state)
	skin = guiGridListGetItemText ( truckerSkinGL, guiGridListGetSelectedItem ( truckerSkinGL ), 1 )
	if skin ~= 0 then
		guiSetVisible(truckerWindow, false)
		showCursor(false)
		triggerServerEvent ( "setTruckerTeam", localPlayer, skin)
	else
		outputChatBox ("** You must choose a skin!", 255, 0, 0, true)
--		exports["SAFtopBar"]:sendClientMessage("You must choose a skin!", 255, 0, 0, true, 8)
	end
end
addEventHandler("onClientGUIClick", btnAccept, takeTruckerJob, false)

 

Problem already solved.

Edited November 18, 2017 by Potato_Tomato420