flanges thereof against the complementary flanges of the channel member 66 on the other hand bolt 74 can be inserted through an aperture provided in the channel member 72 to cooperate with the weld nut 52a provided on the channel member 66 to securely fasten the channel member 72 to the channel member 66 the posts 24 and 24a are then either assembled in the clamp 40 as illustrated in fig2 by wing bolts not shown or to the locking tabs 64a illustrated in fig5 with the pins 24b of the posts inserted into the apertures 14b of the shelf 14 in the embodiment shown in fig2 the back panel 32 is assembled by hooking the flange 32b over the top edges of the flanges 38d and or the flanges 48a and 48b of the end panels 30 30a and or 44 corner braces 46 and 46a see fig2 may be secured to the top marginal corner edges of the end panels 30 30a and the adjacent portion of the flanges 32b for rigidly strengthening the canopy assembly in the embodiment of the invention shown in fig5 the rear cover panel 58 is assembled to the end panel 56 by sliding the flange portion 58d over the complementary flange of the member 70 until the upper flange 58b rests on the top marginal edge of the member 70 the front side panel 34 is then assembled by sliding the open end of the lips 34b and 34c over the adjacent end portions of the flanges 36d.