No, and you shouldn't need to. You can't have multiple values for a single CSS property. That works directly in CSS because the duplicate properties overwrite each other, and in this case is dependent upon the browser. Basically, with that CSS, webkit-based browsers see the webkit-specific property and apply it, then see an unknown property and ignore it. Gecko-based browsers will see an unknown property and ignore it, then see a Mozilla-specific property and apply it.
Try your code in Firefox - I bet it will work just fine, except that it will show the Mozilla property instead of the webkit one.
Also, if this is supposed to be CSS3, you should be able to just use the linear-gradient
instead of the vendor-specific ones, and then it'll work in all CSS3-compatible browsers as well.
EDIT: Well except linear-gradient
isn't actually supported. So instead you should use those vendor-specific values and additionally use -ms-linear-gradient
to support IE, -o-linear-gradient
to support Opera, and also use linear-gradient
for future compatibility. ;)