attempt to index field ' ' (a nil value) ?

I'm making a gui for my game but the button doesn't work for some reason. It can't find the path to something called "EV" in the game cause maybe its next to the tostring thing ,tostring(PokemonEV.Text).EV.HPEV could anyone help please? thanks The script/code was glitched on this website so i put it on a pastebin, Don't worry its a safe link!

https://pastebin.com/rAKvx9zC

Thanks! :D

On line 3:tostring(PokemonEV.Text).EV.HPEV you attempt to find EV.HPEV from a string variable. I'm not sure how to tell you how to fix it as I don't have any context as to what its supposed to do.