Javascript获取窗口高度

	// 获取窗口宽度
   if (window.innerWidth)
   winWidth = window.innerWidth;
   else if ((document.body) && (document.body.clientWidth))
   winWidth = document.body.clientWidth;
   // 获取窗口高度
   if (window.innerHeight)
   winHeight = window.innerHeight;
   else if ((document.body) && (document.body.clientHeight))
   winHeight = document.body.clientHeight;
   // 通过深入 Document 内部对 body 进行检测，获取窗口大小
   if (document.documentElement && document.documentElement.clientHeight && document.documentElement.clientWidth)
   {
	    winHeight = document.documentElement.clientHeight;
	    winWidth = document.documentElement.clientWidth;
   }