Abstract: A supporting mechanism for a window screening device comprises a first pair of bracket members for mounting on each of a pair of opposed parallel frame surfaces of the frame structure and a second pair of coupling members engageable by the screening device. Each bracket member and each coupling member comprises an engaging mechanism for releasable sliding engagement of a coupling member with a bracket member. Each bracket member or each coupling member is provided with a resilient mechanism engageable with an abutment of a coupling member or a bracket member to retain the bracket member and the coupling member in mutual engagement. The bracket members are identical standard members each comprising a relatively flat front part protruding from said frame surface and having a substantially smooth external surface and engaging mechanism formed by a pair of opposed parallel side edges.