ComputerCraft mutiple if conditions

So I try to do an os in computercraft(minecraft mod) and I need to use mutiple conditions. My if looks like this:

if _m = 0 then and button = 1 and x < 6 and y == 19 then
    drawSelectBar()
  end
end

_m is a variable that's equal to 0. Button, x, y are variables get from a os.pullEvent(I have defined the first parameter as event so its not a wrong event). When I run the code it says 'then' expected. What can I do?