resource.addfile help >.>

Ok, so I figured out how to make it work but now I have another problem. People now everytime they reconnect download all the content all over again, so in the meantime I removed the autorun script for it. So how do I fix this?

Someone told me to put this " if file.Exists(“model/hitler.mdl”) then return else resource.AddFile(“model/hitler.mdl”) end" do I have to do that for every model / material?