This is the test1 DIV.
It has these styles:

	width: 300px;
	height: 200px;
	border: 10px solid #666;
	padding: 5px;
	overflow: hidden;

Its total visible width and height are therefore 330 pixels (300 width + 10 padding + 20 border).

This is the test DIV.
This is the test DIV.
This is the test DIV.
This is the test DIV.
This is the test DIV.
This is the test DIV.
This is the test DIV.
This is the test DIV.
This is the test DIV.
This is the test DIV.

This is the test2 DIV.
It has these styles:

	width: 300px;
	height: 200px;
	border: 10px solid #666;
	padding: 5px;
	overflow: auto;

在ie6和ie7中，clientWidth包含滚动条的宽度； 在其它A级浏览器以及ie8 beta1中，clientWidth减去了滚动条的宽度

This is the test DIV.
This is the test DIV.
This is the test DIV.
This is the test DIV.
This is the test DIV.
This is the test DIV.
This is the test DIV.
This is the test DIV.
This is the test DIV.
This is the test DIV.

This is the test3 DIV.
It has these styles:

	width: 300px;
	height: 200px;
	border: 10px solid #666;
	padding: 5px;
	overflow: auto;

在ie6和ie7中，clientWidth == 0
解决办法是通过zoom: 1等方式使得hasLayout为true
注意：此时offsetWidth有值

This is the test4 DIV.
It has these styles:

	width: 300px;
	height: 200px;
	border: 10px solid #666;
	padding: 5px;
	overflow: auto;
	zoom: 1;

#test4和#test5样式完全一样，
但在ie7中，clientWidth的值不同。
当zoom: 1遭遇overflow时，ie7很诡异

This is the test5 DIV.
It has these styles:

	width: 300px;
	height: 200px;
	border: 10px solid #666;
	padding: 5px;
	overflow: auto;
	zoom: 1;

#test4和#test5样式完全一样，
但在ie7中，clientWidth的值不同。
当zoom: 1遭遇overflow时，ie7很诡异