Flex的Scroller组件指定滚动位置

求大神 们 ，帮帮忙

protected function init(event:FlexEvent):void
                        {
                                for(var i:int = 0;i < 100; i++)
                                {
                                        var ahl:AutoWidthLoader = new AutoWidthLoader();
                                        ahl.source = Instance;
                                        ahl.percentHeight = 100;
                                        (ahl.content as Instance).mc1_1.gotoAndStop(1);
                                        (ahl.content as Instance).mc1_2.gotoAndStop(1);
                                        (ahl.content as Instance).mc1_3.gotoAndStop(1);
                                        (ahl.content as Instance).mcId1_1.gotoAndStop(1);
                                        (ahl.content as Instance).mcId1_2.gotoAndStop(1);
                                        (ahl.content as Instance).t1.text = (i+1).toString();
                                        list.addElement(ahl);
                                }
                               
                       
                                trace(sr.maxWidth);
                                list.horizontalScrollPosition = 10/100*list.maxWidth;
                               
                        }
                       
                ]]>
        </fx:Script>
        <fxeclarations>
                <!-- 将非可视元素（例如服务、值对象）放在此处 -->
        </fxeclarations>
        <common:AutoHeightLoader id="View" width="100%" source="{scene}"/>
        <s:Scroller id="sr" top="37" y="20"  width="100%" height="22%" horizontalCenter="0" interactionMode="touch" horizontalScrollPolicy="auto">
                <s:HGroup id="list"  x="10" height="100%" gap="0">
                </s:HGroup>
        </s:Scroller>

我在list里边添加了100个mc，想在开始的时候让滚动条停在第十个mc的位置，请问要怎么实现呢