ImageStyles? Can't get an image to use them

[Haliken]

Ok, I'm trying to add a map selection tab to the map window. I don't want to load the map texture files twice, so I was trying to do this:
<Image ImageStyle="MapStyles.befallen" Location="0,0" Name="QM_Stormhold" ScrollExtent="436,506" Size="436,506"/>
but the ImageStyle= part isn't working.

Does anyone know how to use an ImageStyle in an Image object?

Quib