How to control js elements to display at a fixed position on the screen and monitor screen height changes_javascript skills

//控制logo的显示位置 Begin
window.addEventListener("resize", function () {
  // 得到屏幕尺寸 (内部/外部宽度，内部/外部高度)
  changeLogoPosition();
}, false);
changeLogoPosition();
function changeLogoPosition() {
  var contentHeight = $("#main_content_div").css("height");
  var logoHeight = $("#third_party_logo").css("height");
  contentHeight = parseInt(contentHeight.replace('px', ''));
  logoHeight = parseInt(logoHeight.replace('px', ''));
  //alert('屏幕高度：'+document.body.scrollHeight+' 内容高度：'+contentHeight+' logo高度：'+logoHeight);
  if (document.body.scrollHeight - contentHeight > logoHeight) {
    document.getElementById('third_party_logo').style.position = 'absolute';
  } else {
    document.getElementById('third_party_logo').style.position = '';
  }
}
//控制logo的显示位置 End