installationProgress.macInstallJavaHtml Property

var u = $au.uploader({
    //...other params...
});
var ip = $au.installationProgress(u);
ip.macInstallJavaHtml("<p>Use the <a href=\"http://support.apple.com/kb/HT1338\">Software Update</a> " +
"feature (available on the Apple menu) to check that you have the most up-to-date version of Java for your Mac.</p>");
//...other params...
u.writeHtml();