function encryptString(str,code)
  -- character table
    chars="1234567890!@#$%^&*()qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM ,<.>/?;:'[{]}\|`~"
  -- new code begin
    newcode=""
  -- we start
    for i=1, 999 do
        if string.sub(str,i,i) == "" then
            break
        else
      com=string.sub(str,i,i)
    end
        for x=1, 90 do
      cur=string.sub(chars,x,x)
      if com == cur then
        new=x+code
        while new > 90 do
          new = new - 90
        end
        newcode=""..newcode..""..string.sub(chars,new,new)..""
      end
    end
    end
    print("you new code is: "..newcode.."")
    return newcode
end

function unencryptString(str,code)
  -- character table
    chars="1234567890!@#$%^&*()qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM ,<.>/?;:'[{]}\|`~"
  -- new code begin
    newcode=""
  -- we start
    for i=1, 999 do
        if string.sub(str,i,i) == "" then
            break
        else
      com=string.sub(str,i,i)
    end
        for x=1, 90 do
      cur=string.sub(chars,x,x)
      if com == cur then
        new=x-code
        while new < 0 do
          new = new + 90
        end
        newcode=""..newcode..""..string.sub(chars,new,new)..""
      end
    end
    end
    print("you old string is: "..newcode.."")
    return newcode
end