diff --git a/dist/css/classic/zebra_dialog.css b/dist/css/classic/zebra_dialog.css
index 93e3bc1..98f45d7 100644
--- a/dist/css/classic/zebra_dialog.css
+++ b/dist/css/classic/zebra_dialog.css
@@ -162,7 +162,7 @@ a.ZebraDialog_Close {
     background-image: linear-gradient(to bottom,#08c,#04c);
     background-repeat: repeat-x;
     border-color: rgba(0,0,0,.1) rgba(0,0,0,.1) rgba(0,0,0,.25);
-    filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#FF0088CC', endColorstr='#FF0044CC', GradientType=0);
+    filter: progid:DXImageTransform.Microsoft.gradient(startColorstr="#FF0088CC", endColorstr="#FF0044CC", GradientType=0);
     filter: progid:DXImageTransform.Microsoft.gradient(enabled=false)
 }
 .ZebraDialog_Buttons a:hover {