Gridview validation using sever controls

Default.aspx

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
onrowcancelingedit="GridView1_RowCancelingEdit"
onrowediting="GridView1_RowEditing">

<Columns>
<asp:BoundField DataField ="id" HeaderText ="id" ReadOnly="true" />

<asp:TemplateField HeaderText ="name">
<ItemTemplate >
<asp:Label ID="Label1" runat="server" Text='<%#Eval("name") %>'></asp:Label>

</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="TextBox1" runat="server" Text='<%#Eval("name") %>'></asp:TextBox>
<asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ErrorMessage="Please enter the data" ControlToValidate ="TextBox1"></asp:RequiredFieldValidator>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText ="fathername">
<ItemTemplate >
<asp:Label ID="Label2" runat="server" Text='<%#Eval("fathername") %>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="TextBox2" runat="server" Text='<%#Eval("fathername") %>'></asp:TextBox>
<asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ErrorMessage="Please enter the data" ControlToValidate ="TextBox2" ></asp:RequiredFieldValidator>
</EditItemTemplate>
</asp:TemplateField>
<asp:CommandField ShowEditButton="True" />
</Columns>
</asp:GridView>



Default.aspx.cs

protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindDataToGrid();
}
}
public DataSet BindDataToGrid()
{
SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ToString());
SqlCommand cmd = new SqlCommand("select * from employee", con); SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
GridView1.DataSource = ds;
GridView1.DataBind();
return ds;
}

protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
{
GridView1.EditIndex = e.NewEditIndex;
BindDataToGrid();
}
protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
{
GridView1.EditIndex = -1;
BindDataToGrid();
}