We can use Conditional Comments to select put some CSS only in IE6 implementing the work around. This is a feature only from the Internet Explorer browser.

<!–[if lt IE 7]>
<link rel=”stylesheet” type=”text/css” href=”ie6style.css” />
<![endif]–>

Remember that in the normal CSS you must put a normal CSS background. It must be before the IR6 hack.

background: url(”bkg.png”) top left no-repeat;

If you are worried about the validation, you don’t need to be, because Conditional Comments validate well. The validators like W3C will think that it’s a normal comment.

Another way uses only CSS and try a different approach. Create a class to be read from IE and another one only from another browsers, because the IE browsers ignore classes with attributes, like following:

.bkg {
width:100px;
height:50px;
/* Mozilla ignores MS image filters, so it will skip this filter */
filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, sizingMethod=scale, src=”bkg.png”);
}
/* IE ignores styles with [attributes], so it will skip this class */
.bkg[class] {
background: url(”bkg.png”) top left no-repeat;
}

Now I think you won’t have doubts.