7处ff与ie中读写html、css相关属性的不同之处

1. float样式属性

IE syntax:

document.getElementById("test").style.styleFloat = "left";

FF syntax:

document.getElementById("test").style.cssFloat = "left";

2.获取计算之后的元素样式

IE syntax:

var element = document.getElementById("test"),
  elementStyle = element.currentStyle.backgroundColor;

FF syntax:

var element = document.getElementById("test"),
  computedStyle = document.defaultView.getComputedStyle(element, null),
  elementStyle = computedStyle.backgroundColor;

3.获得元素的"class"属性

IE syntax:

var element = document.getElementById("test"),
  classAttr = element.className;
 //or
  classAttr = element.getAttribute("className");

FF syntax:

var element = document.getElementById("test"),
  classAttr = element.getAttribute("class");

4.获取元素的“for”属性

IE syntax:

var element = document.getElementById("test"),
 forAttr = element.getAttribute("htmlFor");

FF syntax:

var element = document.getElementById("test"),
 forAttr = element.getAttribute("for");

5.获得鼠标的坐标位置

IE syntax:

var positionX = event.clientX,
  positionY = event.clientY;

FF syntax:

var positionX = event.pageX,
  positionY = event.pageY;

6.获取viewport，浏览器可用区域大小

IE syntax:

var browserViewportWidth = document.documentElement.clientWidth,
      browserViewportHeight = document.documentElement.clientHeight;

FF syntax:

var browserViewportWidth = window.innerWidth,
      browserViewportHeight = window.innerHeight;

7.alpha 透明度

IE syntax:

#test{
  filter: alpha(opacity=50);
}

var element = document.getElementById("test");
element.style.filter = "alpha(opacity=80)";

FF syntax:

#test{
  opacity: 0.5
}

var element = document.getElementById("test");
element.style.opacity = "0.8";

参考：http://www.impressivewebs.com/7-javascript-differences-between-firefox-ie/