<% Html.Obout(new ComboBox("ComboBox1")
    {   
        SelectedIndex = 4
    }); %>
    
    <% Html.Obout(new OboutButton("OboutButton1")
    {
        OnClientClick = "return moveUp();",
    }); %>	   

    <% Html.Obout(new OboutButton("OboutButton2")
    {
        OnClientClick = "return moveUp();",
    }); %>	   
    
    

    @Html.Obout(new ComboBox("ComboBox1")
    {   
        SelectedIndex = 4
    })
    
    @Html.Obout(new OboutButton("OboutButton1")
    {
        OnClientClick = "return moveUp();",
    })

    @Html.Obout(new OboutButton("OboutButton2")
    {
        OnClientClick = "return moveUp();",
    })
    
    

    function moveUp() {
        var selectedIndex = ComboBox1.selectedIndex();

        if (selectedIndex > 0) {
            var value = ComboBox1.options[selectedIndex].value;
            var text = ComboBox1.options[selectedIndex].text;

            ComboBox1.options.remove(selectedIndex);

            ComboBox1.options.add(text, value, selectedIndex - 1);

            ComboBox1.selectedIndex(selectedIndex - 1);
        }

        return false;
    }

    function moveDown() {
        var selectedIndex = ComboBox1.selectedIndex();

        if (selectedIndex < ComboBox1.options.length - 1) {
            var value = ComboBox1.options[selectedIndex].value;
            var text = ComboBox1.options[selectedIndex].text;

            ComboBox1.options.remove(selectedIndex);

            ComboBox1.options.add(text, value, selectedIndex + 1);

            ComboBox1.selectedIndex(selectedIndex + 1);
        }

        return false;
    }