function ROT13()
	local sel = editor:GetSelText();
	local length = string.len(sel);
	local itt = 1;
	local tempChar;
	local tempString = "";
	
	while itt < length+1 do 
		tempChar = string.sub(sel,itt,itt);
		if (tempChar >= "a" and tempChar <= "m") or (tempChar >= "A" and tempChar <= "M") then
			local x = string.byte(tempChar);
			local y = string.char(x+13);
			tempString =  tempString .. y;
			
		elseif (tempChar >= "n" and tempChar <= "z") or (tempChar >= "N" and tempChar <= "Z") then
			local x = string.byte(tempChar);
			local y = string.char(x-13);
			tempString = tempString .. y;
		else
			tempString = tempString .. tempChar;
		end 
		
		itt=itt+1;
	end

	editor:ReplaceSel(tempString);
end