Allow user to check one CheckBox using C# in ASP.Net

I want users to only select one option. That means the user can only check one checkbox then submit the data to database.

<div class="pull-left" style="margin-left:6px;"">
	<h4 id="name" class="list-group-item-heading" runat="server">name</h4>
</div>
<br  style="margin-bottom:2px; margin-top:2px"/>
<div class="pull-right">
	<asp:CheckBox ID="chkname" runat="server"  CssClass=" " />
</div>
<div class="pull-left" style="margin-left:6px;">
	<h4 id="username" class="list-group-item-heading" runat="server">username</h4>
</div>
<br  style="margin-bottom:2px; margin-top:2px"/>
<div class="pull-right">
  <asp:CheckBox ID="chkusername" runat="server" CssClass="" />
</div>

protected void Save(object sender, EventArgs e)
{
		string userName = Session["UserName"].ToString();
		if (chkname.Checked)
        {
            SaveDetails(userName, name.InnerHtml.Trim());
        }
		if (chkusername.Checked)
        {
            SaveDetails(userName, username.InnerHtml.Trim());
        }
}

public void SaveDetails(string userName, string Favorites)
{
       using (SqlConnection con = new SqlConnection(constring))
       {
           using (SqlCommand cmd = new SqlCommand("INSERT INTO Favorite values(@UserName,@Favorites)", con))
           {
               cmd.Parameters.AddWithValue("@UserName", userName);
               cmd.Parameters.AddWithValue("@Favorites", Favorites);
               con.Open();
               cmd.ExecuteNonQuery();
               con.Close();
           }
       }
}