Format GridView column 2 SQL column values to be separated by a symbol

I have a GridView with one column which contains 2 values from SQL, from columns Author and Author2. In my table there is only one row which has values in both columns, others have only one Author and a NULL. I want to separate only those with both authors with a symbol "&".

I have tried doing this several ways, the first one is with CSS:

<head>
<style> 
.label2css:before {
content: "& ";
}
</style>  
</head>

...

<ItemTemplate>
<asp:Label ID="Label1" runat="server" Text='<%# Bind("Author") %>'></asp:Label> 
<asp:Label ID="Label2" CssClass="label2css" runat="server" Text='<%# Eval("Author2") %>'></asp:Label>
</ItemTemplate>

and the other one:

<ItemTemplate>
<asp:Label ID="Label1" runat="server" Text='<%# Bind("Author") %>'></asp:Label> 
<asp:Label ID="Label2" runat="server" Text='<%# "&" + Eval("Author2") %>'>   </asp:Label>
</ItemTemplate>

But both resulted in this:
Author &
Author & Author2
Author &

But I want to be able to do this:
Author
Author & Author2
Author

Is there a way to do it?

Solution

I would do like this:

<ItemTemplate>
    <asp:Label ID="Label1" runat="server" Text='<%# Bind("Author") %>'></asp:Label> 
    <asp:Label ID="Label2" runat="server" Text='<%#  String.IsNullOrEmpty(Eval("Author2") as string) ? "" : Eval("Author2", "& {0}") %>'>   </asp:Label>
</ItemTemplate>

Here's my test code.

The markup:

<asp:GridView ID="GridView1" AutoGenerateColumns="false"  runat="server">
    <Columns>
        <asp:TemplateField>
            <ItemTemplate>
                <asp:Label ID="Label1" runat="server" Text='<%# Bind("Author") %>'></asp:Label>
                <asp:Label ID="Label2" runat="server" Text='<%# String.IsNullOrEmpty(Eval("Author2") as string) ? "" : Eval("Author2", "& {0}") %>'>   </asp:Label>
                </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>

The code:

public partial class WebForm3 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

        GridView1.DataSource = new List<MyClass>(){
            new MyClass { Author="Author"},
            new MyClass { Author="Author", Author2="Author2"},
            new MyClass { Author="Author"}

        };

        GridView1.DataBind();
    }
}

public class MyClass
{
    public string Author { get; set; }
    public string Author2 { get; set; }
}

And here's the output:

enter image description here