designates a corner post assembly that includes a main support tube 11 at least one side member 12 extending alongside that tube for substantially its full length a pair of upper and lower end caps 13 and 14 respectively that secure the side member 12 and tube 11 together as well as performing other functions and a vertical riser 15 connected to each side member 12 the riser may extend the full height of the side member or as indicated in fig2 the riser 15 39 may have a length height less than that of the side member thus the length of the riser may be selected to meet the needs of the user and to suit the requirements of a particular installation the term 34 riser 34 is used here to mean a vertical member that would ordinarily be a component of a panel or frame structure intended to be connected to and supported by the corner post assembly for example in fig2 risers 15 and 15 39 constitute the vertical side members of panel structures p and p 39 respectively whether the structure constitutes an open panel a closed panel or is used for screening or to provide support for shelving or furniture components is not material to this disclosure panel structures and their uses are well known in the art and for purposes of describing this invention it is believed sufficient to point out that the utility of the riser lies in the fact that it constitutes the side member of what might otherwise be.