if ( $(window).width() <= 860 ) {
    $('.conversion-form').detach().insertBefore('.main-content');
}
$(window).on('resize', function(){
    var win = $(this);
    if (win.width() <= 860) {
        $('.conversion-form').detach().insertBefore('.main-content');
    } else if (win.width() >= 861) {
        $('.conversion-form').detach().prependTo('.col.sidebar');
    }
});