如何在魔兽3地图编辑器中制作一个判断单位是否移动的函数呢？

function UnitStandCheck takes unit U returns nothing
    local unit WitchUnit = U
    local unit RespondingUnit = null
    local location UnitLoc = GetUnitLoc(WitchUnit)
    local boolean IsStanding = true
    local trigger RespondingTrigger = null

    loop
        if (IsStanding == true) then
            if (DistanceBetweenPoints(UnitLoc, GetUnitLoc(WitchUnit)) > 10 ) then)
                set RespondingUnit = CreateUnitAtLoc(GetOwningPlayer(WitchUnit), 'hhdl', Location(0, 0), 0.00)
                set IsStanding = false

                set RespondingTrigger = CreateTRigger()
                call TriggerRegisterAnyUnitEventBJ(RespondingTrigger,EVENT_PLAYER_UNIT_DEATH)
                call TriggerAddAction(RespondingTrigger, function RespondingAction)

                call ExplodeUnitBJ(RespondingUnit)
                call SetUnitUserData(WitchUnit, 0)
                //自定义事件(未移动)
            endif
        else
            if (DistanceBetweenPoints(UnitLoc, GetUnitLoc(WitchUnit)) <= 10 ) then)
                set RespondingUnit = CreateUnitAtLoc(GetOwningPlayer(WitchUnit), 'hrdh', Location(0, 0), 0.00)
                set IsStanding = true

                set RespondingTrigger = CreateTRigger()
                call TriggerRegisterAnyUnitEventBJ(RespondingTrigger,EVENT_PLAYER_UNIT_DEATH)
                call TriggerAddAction(RespondingTrigger, function RespondingAction)

                call ExplodeUnitBJ(RespondingUnit)
                call SetUnitUserData(WitchUnit, 0)
                //自定义事件(移动中)
            endif
        endif

        set UnitLoc = GetUnitLoc(WitchUnit)
        call PolledWait(0.01)
    endloop
endfunction