ui combobox selected

// Destroy the combobox
$(".combobox").combobox("destroy");

// Unselect the currently selected option
$("#selectlist option:selected").removeAttr("selected");

// Select the option you want to select
$("#selectlist option[value='test']").attr("selected", "selected");

// Create the combobox again
$(".combobox").combobox();

$('#scale').val('square');
$("#scale").selectmenu("refresh");

      function combobox_select(el,val){
            $(el).combobox("destroy");
            $(el+' option:selected').removeAttr("selected");
            $(el+' option[value="'+val+'"]').attr("selected", "selected");
            $(el).combobox();

  }
//
                    $('#dvid option:selected').removeAttr("selected");
                    $("#dvid option[value='"+dvid+"']").attr("selected", "selected");
                    $("#dvid").selectmenu("refresh");



 $('#combobox option:selected').removeAttr("selected");
            $('#combobox  option[value="'+prepId+'"]').attr("selected", "selected");
           $('#combobox').parent().find(".custom-combobox-input").val($("#combobox option[selected]").text());


             $('#role option:selected').removeAttr("selected");
            $('#role  option[value="'+roleId+'"]').attr("selected", "selected");
           $('#role').parent().find(".ui-selectmenu-text").text($("#role option[selected]").text());


 $('#combobox option:selected').removeAttr("selected");
            $('#combobox  option[value="'+v+'"]').attr("selected", "selected");
           $('#combobox').parent().find(".custom-combobox-input").val($("#combobox option[selected]").text());


             $('#role option:selected').removeAttr("selected");
            $('#role  option[value="'+v+'"]').attr("selected", "selected");
           $('#role').parent().find(".ui-selectmenu-text").text($("#role option[selected]").text());

    $('#combobox option[selected]').removeAttr("selected");
            $('#combobox  option[value="'+prepId+'"]').prop({defaultSelected: true});

 $('#n-job option:selected').removeAttr("selected");
            $('#n-job  option[value="'+$(this).data('job')+'"]').prop({defaultSelected: true});
             $("#n-job").selectmenu("refresh");