Abstract: Corner members and frame members forming an assembly is provided, for holding a screen or the like, in which the corner members have arms disposed to be connected to frame members, preferably by being telescopically received therein, for facilitating retaining the frame assembly, which is a removable assembly, inside a fixed frame of a window. Upper corner members of a moveable frame have a U-shaped attachment means formed by an upwardly projecting flange and tab forming U-shaped channels. The top of the frame having the U-shaped attachment means is inserted at an angle into a downwardly projecting lip means on a fixed frame such that the U-shaped attachment means loosely embraces the lip means. The moveable frame is rotated until the U-shaped attachment means fully embraces the lip means, the moveable frame is flush with fixed frame, and the moveable frame is locked into position against the fixed frame with retaining mechanisms on the remaining two corners of the moveable frame.