Abstract: A container having multiple wall panels forming container sides, the container having at least first and second wall panels that meet at a first corner. The container is assembleable from a flat or knockdown state to an opened or assembled state. A first inner panel is attached to a first wall panel, the first inner panel having an end spaced from the first corner. A slidable corner support is attached to the end of the first inner panel and extends towards the second wall panel. When the container is assembled from the knockdown state, the slidable corner support moves away from the first corner to form a support member that can help support a container stacked on top and prevent nesting.