dotted和dashed有IE下没有什么区别，但是在Firefox下就区别明显了，dotted的属于就变成了solid，直线的一条，并不是点线。

The border-style property sets the style of the four borders, can have from one to four styles.

border-style 属性可设置四边的样式，可以有1到4种样式

继承性: 无

举例
table {border-style: dotted}

all four borders will be dotted

四条边都为打点型table {border-style: dotted dashed}

top and bottom border will be dotted, left an right border will be dashed

上下边为打点型的，左右为粉碎型

table {border-style: dotted dashed solid}

top border will be dotted, left and
right border will be dashed, bottom border will be solid

上边为打点型，左右为粉碎型边框，下边框为线型

table {border-style: dotted dashed solid double}

top border will be dotted,
right border will be dashed, bottom border will be solid, left border
will be double

上边为打点型，右边为粉碎型，下边为线型，左边为双线型

可用值
值 描述
none Defines no border

无边框

hidden The same as “none”, except in border conflict
resolution for table elements

除了在table元素的边框解析上有冲突外基本和”none”一样

dotted Defines a dotted border. Renders as solid in most
browsers

打点边框，在大多数浏览器中会变为线条

dashed Defines a dashed border. Renders as solid in most
browsers

断裂边框，在大多数浏览器下也会变为线条(在IE里dotted和dashed基本无区别，FF浏览器有所不同)

solid Defines a solid border

线条边框

double Defines two borders. The width of the two borders are the
same as the border-width value

双线边框。两线的宽度和border-width值一样

groove Defines a 3D grooved border. The effect depends on the
border-color value

3D沟槽边框。效果依赖于border-color的值

ridge Defines a 3D ridged border. The effect depends on the
border-color value

3D脊状边框。效果依赖于border-color的值

inset Defines a 3D inset border. The effect depends on the
border-color value

3D嵌入边框。效果依赖于border-color的值

outset Defines a 3D outset border. The effect depends on the
border-color value

3D突出边框。效果依赖于border-color的值