Important to remember that if you put the filter property in with the rest of your CSS, the path to the image needs to be relative to the page, not the CSS file. So:
/page.html /css/css.css /images/png.png
background-image:url(../images/png.png); _background-image:none; _filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src='images/png.png', sizingMethod='scale');
<code>
<blockcode>
<csharp>
<css>
<html>
<javascript>
<vb>
<vbnet>
<xml>
<foo>
[foo]
More information about formatting options
Relative paths
Important to remember that if you put the filter property in with the rest of your CSS, the path to the image needs to be relative to the page, not the CSS file. So:
/page.html
/css/css.css
/images/png.png