After activating the Raster Info tool the dialog will let you choose the layer to be used for identification.

 

Note: Only layers that have been configured as raster info layers be listed.

 

 

Simply click into the map in order to request the raster value. The result will be shown in the box below the choice of raster layers.

 

 

Note: See chapter Raster Info for details about the tool configuration in WebOffice author.