CSS hack in different browsers

Difference IE6 with FF:

Background:orange;*background:blue;

Distinction between IE6 and IE7:

Background:green!important;background:blue;

Difference IE7 with FF:

Background:orange; *background:green;

Difference ff,ie7,ie6:

Background:orange;*background:green!important;*background:blue;

Note: IE can recognize *; standard browsers (such as FF) cannot recognize *;

IE6 can recognize *, but cannot recognize!important,

IE7 can recognize the *, also can identify!important;

FF does not recognize *, but can identify!important;

IE6 IE7 FF

*√√x

!importantx√√

Add another, underline "_" in addition,

IE6 supports underscores, IE7 and Firefox do not support underscores.

So we can differentiate Ie6,ie7,firefox.

: Background:orange;*background:green;_background:blue;

Note: No matter what method, the order of writing is Firefox written in the front, IE7 written in the middle, IE6 written in the last side.