jQuery 获取屏幕高度、宽度

alert($(window).height()); //浏览器当前窗口可视区域高度   alert($(document).height()); //浏览器当前窗口文档的高度   alert($(document.body).height());//浏览器当前窗口文档body的高度   alert($(document.body).outerHeight(true));//浏览器当前窗口文档body的总高度 包括border padding margin   alert($(window).width()); //浏览器当前窗口可视区域宽度   alert($(document).width());//浏览器当前窗口文档对象宽度   alert($(document.body).width());//浏览器当前窗口文档body的高度   alert($(document.body).outerWidth(true));//浏览器当前窗口文档body的总宽度 包括border padding margin      // 获取页面的高度、宽度  function getPageSize() {      var xScroll, yScroll;      if (window.innerHeight && window.scrollMaxY) {          xScroll = window.innerWidth + window.scrollMaxX;          yScroll = window.innerHeight + window.scrollMaxY;      } else {          if (document.body.scrollHeight > document.body.offsetHeight) { // all but Explorer Mac                  xScroll = document.body.scrollWidth;              yScroll = document.body.scrollHeight;          } else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari                  xScroll = document.body.offsetWidth;              yScroll = document.body.offsetHeight;          }      }      var windowWidth, windowHeight;      if (self.innerHeight) { // all except Explorer              if (document.documentElement.clientWidth) {              windowWidth = document.documentElement.clientWidth;          } else {              windowWidth = self.innerWidth;          }          windowHeight = self.innerHeight;      } else {          if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode                  windowWidth = document.documentElement.clientWidth;              windowHeight = document.documentElement.clientHeight;          } else {              if (document.body) { // other Explorers                      windowWidth = document.body.clientWidth;                  windowHeight = document.body.clientHeight;              }          }      }             // for small pages with total height less then height of the viewport          if (yScroll < windowHeight) {          pageHeight = windowHeight;      } else {          pageHeight = yScroll;      }          // for small pages with total width less then width of the viewport          if (xScroll < windowWidth) {          pageWidth = xScroll;      } else {          pageWidth = windowWidth;      }      arrayPageSize = new Array(pageWidth, pageHeight, windowWidth, windowHeight);      return arrayPageSize;  }     // 滚动条  document.body.scrollTop;  $(document).scrollTop();