css hacks
* html selector /* for IE6 and below */
*+html selector /* for IE7 and IE5 */
*:first-child+html selector /* for IE7 only */
html>body selector /* for IE7+ and other standard browsers */
html>/**/ body selector /* for not IE */
_property:value /* for IE6 and below */
*property:value /* for IE7、6、5 */
porperty:value\0/ /* for IE8 */
porperty:value\9 /* for all IE */