??<script>????var box = document.getElementById('box');???????????//獲取內聯(lián)樣式的屬性top????var sheet = document.styleSheets[0];????var rules = sheet.cssRules || sheet.rules;????var rule = rules[1];???????window.onscroll = function(){?????//框框距離頂端的距離?????var distance = box.offsetTop;????????//獲取滾動條距離頂部的位置?????var sTop = document.body.scrollTop || document.documentElement.scrollTop || window.pageYOffset;??????? ?????rule.style.top = parseInt(sTop)+parseInt(distance)+'px';????????}??</script>