在實現控制條的收縮的時候for (var i = 0; i < aA.length; i++) {?????? aA[i].onmouseover = function(){???????? var This = this;???????? clearInterval(This.time);???????? This.time = setInterval(function(){??????????? This.style.width = This.offsetWidth + 8 + "px";??????????? if(This.offsetWidth >= 160)??????????????? clearInterval(This.time);???????? }, 30)?????? }????? aA[i].onmouseout = function(){??????? clearInterval(this.time);??????? var This = this;??????? this.time = setInterval(function(){??????????? This.style.width = This.offsetWidth - 8 + "px";??????????? if(This.offsetWidth <= 120)??????????? {??????????????? This.style.width = '120px';??????????????? clearInterval(This.time);??????????? }????????????????????????????????? }, 30)????? }onmouseover在使用this的時候一直都是使用重定義后的This,然而在onmouseout中卻是直接使用this才能實現收縮的效果，請問this的使用有什么技巧和要求嗎？