globals
unit array u
integer count = 0
timer t = CreateTimer()
endglobals

function xXx takes nothing returns nothing
local integer i = 1
      loop
            exitwhen i > count
            call SetUnitX(u[i],GetUnitX(u[i])+20)
            call SetUnitY(u[i],GetUnitY(u[i])+20)
            if GetUnitX(u[i])>100 or GetUnitY(u[i]) > 100 then
                  call KillUnit(u[i])
                  set u[i] = u[count]
                  set u[count] = null
                  set count = count - 1
                  set i = i - 1
            endif
            set i = i + 1
      endloop
      if count == 0 then
            call TimerPause(t)
      endif
endfunction

function xxx takes nothing returns nothing
      set count = count + 1
      set u[count] = CreateUnit(Player(0),'hpea',0,0,0)
      if count == 1 then
            call TimerStart(t,0.1,true,function xXx)
      endif
endfunction