The RPG Maker Resource Kit

WHen i use magic like fire or greater fire or mi fire~ it says Script`Scene_Battle4'line76: argument occured. wrong number of arguments(0-1)...never mind it happens when i use any skill...what do i do

Is this the code?
def update_phase4
    case @phase4_step
    when 1
      update_phase4_step1
    when 2
      update_phase4_step2
    when 3
      update_phase4_step3
    when 4
      update_phase4_step4
    when 5
      update_phase4_step5
    when 6
      update_phase4_step6
    end
  end

Note:line j76 is step2

yup

need help i cant test out battle