A child alert system that uses radio transmitters and receivers to provide the location of a child, adult or object to which a transmitter unit of the system is attached. A carrying bag, and in particular a backpack, includes a rear compartment formed in part from an expandable material for receiving oversized items such as basketballs, soccer balls, footballs and the like. Thus, the slide member has a plurality of passages having different positions for mounting the vertical slats so that the track can be used to combine with multiple vertical slats, and the vertical curtain is available for windows having larger sizes, thereby enhancing the versatility of the vertical curtain.