$(document).on("ready", function() {
    var lnk = document.location.pathname;
    if( $lnk=="/page1/" ){
        $.("#div_id").toggleClass('page-1');
    }else if( $lnk=="/page1/" ){
        $.("#div_id").toggleClass('page-2');
    }else if( $lnk=="/page1/" ){
        $.("#div_id").toggleClass('page-3');
    }
});