alias toggle_help {
  $iif(%help == 1, %help = 0, %help = 1)
  $iif(%help == 1, mode $me -h, mode $me +h)
}

You don\'t really need the same thing in both situations, so you could just do

  %help = $iif(%help,0,1)
  mode $me $iif(%help,-h,+h)