custom slider

var $j = jQuery.noConflict();

$j(function(){

    //** MAIN LAYOUT **//
    var main_page_width = $j('input[name="theme_options[main_page_width]"]').val();

    // wait till iframe has been loaded
    setTimeout(function() {

        // Main Page Width
        $j('input[name="theme_options[main_page_width]"]').next('div.slider').slider({
            value: main_page_width,
            min: 800,
            max: 1200,
            slide: function( event, ui ) {

                // Change input value and slider position
                $j('input[name="theme_options[main_page_width]"]').val( ui.value ).change();

                // Change CSS in LivePreview
                $j("iframe").contents().find('div.container').css('width', ui.value+'px');

            }
        });

    });

});