通过javascript设置css属性的代码

opacity:.75;//ff new
-moz-opacity:.75;// transparency for older Mozillas
filter:Alpha(opacity=75);//for IE

element.style.fontFamily = "sans-serif";
element.style.borderLeftWidth = "5px";
element.style.zIndex = 100;

var padding_left = 50;
element.style.left = padding_left + "px";//不要忘记加单位
var topMargin = 10,rigntMargin = 11,bottomMargin = 12,leftMargin = 13;
element.style.margin = topMargin + "px" + rigntMargin + "px" + bottomMargin + "px" + leftMargin + "px";

element.style.cssFloat = "left";//firefox chrome opera
element.style.styleFloat = "left";//IE