자바스크립트 카운터되는 소스에 setTimeout 적용하고 싶은데요 ㅠㅠ 채택완료

</p><p>  <script type="text/javascript"></p><p>function numberCounter(target_frame, target_number) {</p><p><span class="Apple-tab-span" style="white-space:pre">	</span>this.count = 0; this.diff = 0;</p><p>    this.target_count = parseInt(target_number);</p><p>    this.target_frame = document.getElementById(target_frame);</p><p>    this.timer = null;</p><p>    this.counter();</p><p>};</p><p>    numberCounter.prototype.counter = function() {</p><p>        var self = this;</p><p>        this.diff = this.target_count - this.count;</p><p>    </p><p>        if(this.diff > 0) {</p><p>            self.count += Math.ceil(this.diff / 5);</p><p>        }</p><p>    </p><p>        this.target_frame.innerHTML = this.count.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ',');</p><p>  <span class="Apple-tab-span" style="white-space:pre">	</span> </p><p>        if(this.count < this.target_count) {</p><p>            this.timer = setTimeout(function() { self.counter(); }, 100);</p><p>        } else {</p><p>            clearTimeout(this.timer);</p><p>        }</p><p>    };</p><p><span class="Apple-tab-span" style="white-space:pre">		</span></p><p><span class="Apple-tab-span" style="white-space:pre">	</span>new numberCounter("counter4", 1270);<span class="Apple-tab-span" style="white-space:pre">	</span></p><p><span class="Apple-tab-span" style="white-space:pre">	</span>new numberCounter("counter3", 483);</p><p><span class="Apple-tab-span" style="white-space:pre">	</span>new numberCounter("counter2", 167300);</p><p><span class="Apple-tab-span" style="white-space:pre">	</span>new numberCounter("counter1", 4235);</p><p> </p><p><span class="Apple-tab-span" style="white-space:pre">	</span></script></p><p>