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This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.


Requires Gecko 21.0(Firefox 21.0 / Thunderbird 21.0 / SeaMonkey 2.18)


If the user is using Windows Glass theme, this is 1; otherwise it's 0. Note that this only exists for Windows 7 and earlier.

Media: media/visual
Accepts min/max prefixes: no

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 Contributors to this page: mfluehr
 Last updated by: mfluehr,