An enclosure including at least one elongate, substantially planar wall member and at least one post member having at least one each channel, each at least one wall member having an edge which fits into at least one edge channel, the edge of the wall member having a plurality of spaced apart projections which extend from each side of the wall member, the edge channel having a pair of spaced apart, substantially parallel flanges between which the edge of a wall member is received and an abutment shoulder on at least one of the substantially parallel flanges in order to engage the projections on the wall member to allow passage thereof in a first direction but prevent passage in a second, opposite direction.
