latest7daysMasteredWordsCountByDay

getScrollTop.js

    function getScrollTop() {
      var scroll_top = 0
      if (document.documentElement && document.documentElement.scrollTop) {
        scroll_top = document.documentElement.scrollTop
      } else if (document.body) {
        scroll_top = document.body.scrollTop
      }
      return scroll_top
    }