CSS Hacks for Internet Explorer 7

Like IE6 ,IE7 also needs some hacks some times.For that we need to write the css something like given below

.style1{ padding:10px 0 0 20px;}

If this css will have any problems in IE7 then we need to write the css like

.style1{ padding:10px 0 0 20px; !padding:10px 0 0 18px;}

Using ( ! ) sign indicates that this css will render by both IE7 and IE6 not in other browser.