'guiGridListGetItemText' Problem

vs_grid1 = guiCreateGridList(0.081,0.1923,0.3327,0.2972,true,vs_Window)
guiGridListSetSelectionMode(vs_grid1,2)
guiGridListAddColumn(vs_grid1,"Felgen",0.8)
for i = 1, 7 do
    guiGridListAddRow(vs_grid1)
end
guiGridListSetItemText(vs_grid1,0,1,"Felge 1 - 15 BP", false, false)
guiGridListSetItemText(vs_grid1,1,1,"Felge 2 - 15 BP", false, false)
guiGridListSetItemText(vs_grid1,2,1,"Felge 3 - 15 BP", false, false)
guiGridListSetItemText(vs_grid1,3,1,"Felge 4 - 15 BP", false, false)
guiGridListSetItemText(vs_grid1,4,1,"Felge 5 - 15 BP", false, false)
guiGridListSetItemText(vs_grid1,5,1,"Felge 6 - 20 BP", false, false)
guiGridListSetItemText(vs_grid1,6,1,"Felge 7 - 20 BP", false, false)

function felgenSel (state)
    if state == "left" then
		if source == vs_button1 then
			row, col = guiGridListGetSelectedItem (vs_grid1)
			if ( row ~= -1 and col ~= -1 ) then
				if guiGridListGetItemText (vs_grid1, row, col) == "Felge 1 - 15 BP" then
					outputChatBox("Hallo!")
				end
			end
		end
	end
end	
addEventHandler("onClientGUIClick", getRootElement(), felgenSel)