Display gridview based on dropdownlist

<asp:DropDownList ID="ddlView" runat="server"
        onselectedindexchanged="ddlView_SelectedIndexChanged" AutoPostBack="true">
        <asp:ListItem Value="Select" Text="Select.."></asp:ListItem>
    <asp:ListItem Value="FirstGrid" Text="First Grid"></asp:ListItem>
     <asp:ListItem Value="SecondGrid" Text="Second Grid"></asp:ListItem>
      <asp:ListItem Value="ThirdGrid" Text="Third Grid"></asp:ListItem>
    </asp:DropDownList>
   <asp:GridView ID="gvFirst" runat="server">
   </asp:GridView>
   <asp:GridView ID="gvSecond" runat="server">
   </asp:GridView>
   <asp:GridView ID="gvThird" runat="server"></asp:GridView>

protected void ddlView_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (ddlView.SelectedValue.ToString() == "Select")
            {
                gvFirst.DataSource = null;
                gvFirst.DataBind();
                gvSecond.DataSource = null;
                gvSecond.DataBind();
                gvThird.DataSource = null;
                gvThird.DataBind();
            
            }
            else if (ddlView.SelectedValue.ToString() == "FirstGrid")
            {
                DataTable table = new DataTable();               
                table.Columns.Add("Selection", typeof(string));
                table.Rows.Add("First Grid");
                gvFirst.DataSource = table;
                gvFirst.DataBind();
                gvSecond.DataSource = null;
                gvSecond.DataBind();
                gvThird.DataSource = null;
                gvThird.DataBind();
                
            }
            else if (ddlView.SelectedValue.ToString() == "SecondGrid")
            {
                DataTable table = new DataTable();
                table.Columns.Add("Selection", typeof(string));
                table.Rows.Add("Second Grid");
                gvSecond.DataSource = table;
                gvSecond.DataBind();
                gvFirst.DataSource = null;
                gvFirst.DataBind();
                gvThird.DataSource = null;
                gvThird.DataBind();

            }
            else
            {
                DataTable table = new DataTable();
                table.Columns.Add("Selection", typeof(string));
                table.Rows.Add("Third Grid");
                gvThird.DataSource = table;
                gvThird.DataBind();
                gvFirst.DataSource = null;
                gvFirst.DataBind();
                gvSecond.DataSource = null;
                gvSecond.DataBind();

            }
        }