(C#) ASP.NET GridView Control - DropDownList in GridView

<%@ Page Language="C#" Debug="true" %>
<%@ import Namespace="System.Data" %>
<%@ import Namespace="System.Data.OleDb" %>
<script runat="server">
	OleDbConnection objConn;
	OleDbCommand objCmd;
	String strSQL;

    void Page_Load(object sender,EventArgs e)
	{
		String strConnString;
		strConnString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + 
		Server.MapPath("database/mydatabase.mdb") + ";";
		objConn = new OleDbConnection(strConnString);
		objConn.Open();
		
		if(!Page.IsPostBack)
		{
			BindData();
		}
    }

	void BindData()
	{
		String strSQL;
		strSQL = "SELECT * FROM customer";

		OleDbDataReader dtReader;
		objCmd = new OleDbCommand(strSQL, objConn);
		dtReader = objCmd.ExecuteReader();
		
	   //*** BindData to GridView ***//
	   myGridView.DataSource = dtReader;
	   myGridView.DataBind();

		dtReader.Close();
		dtReader = null;
		objConn.Close();
		objConn = null;

	}

	public DataTable DataTableCountryCode()
	{
		String strConnString = null;
		OleDbDataAdapter dtAdapter = OleDbDataAdapter;
		DataTable dt = new DataTable();

		strConnString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("database/mydatabase.mdb") + ";";
		objConn = new OleDbConnection(strConnString);
		objConn.Open();

		string strSQL = null;
		strSQL = "SELECT * FROM country";

		dtAdapter = new OleDbDataAdapter(strSQL, objConn);
		dtAdapter.Fill(dt);

		dtAdapter = null;

		return dt;

	}

	void modEditCommand(Object sender, GridViewEditEventArgs e)
	{
		myGridView.EditIndex = e.NewEditIndex;
		myGridView.ShowFooter = false;
		BindData();
	}

	void modCancelCommand(Object sender, GridViewCancelEditEventArgs e)
	{
		myGridView.EditIndex = -1;
		myGridView.ShowFooter = true;
		BindData();
	}

	void modDeleteCommand(Object sender, GridViewDeleteEventArgs e)
	{
		strSQL = "DELETE FROM customer WHERE CustomerID = '" + myGridView.DataKeys[e.RowIndex].Value + "'";
		objCmd = new OleDbCommand(strSQL, objConn);
		objCmd.ExecuteNonQuery();

        myGridView.EditIndex = -1;
        BindData();
	}

    void myGridView_RowCommand(Object source , GridViewCommandEventArgs e)
	{
        if (e.CommandName == "Add")
        {
            //*** CustomerID ***//
            TextBox txtCustomerID = (TextBox)myGridView.FooterRow.FindControl("txtAddCustomerID");
            //*** Name ***//
            TextBox txtName = (TextBox)myGridView.FooterRow.FindControl("txtAddName");
            //*** Email ***//
            TextBox txtEmail = (TextBox)myGridView.FooterRow.FindControl("txtAddEmail");
            //*** CountryCode ***//
            DropDownList ddlCountryCode = (DropDownList)myGridView.FooterRow.FindControl("ddlAddCountryCode");
            //*** Budget ***//
            TextBox txtBudget = (TextBox)myGridView.FooterRow.FindControl("txtAddBudget");
            //*** Used ***//
            TextBox txtUsed = (TextBox)myGridView.FooterRow.FindControl("txtAddUsed");

            strSQL = "INSERT INTO customer (CustomerID,Name,Email,CountryCode,Budget,Used) " +
                " VALUES ('" + txtCustomerID.Text + "','" + txtName.Text + "','" + txtEmail.Text + "' " +
                " ,'" + ddlCountryCode.SelectedItem.Value + "','" + txtBudget.Text + "','" + txtUsed.Text + "') ";
            objCmd = new OleDbCommand(strSQL, objConn);
            objCmd.ExecuteNonQuery();

            BindData();
        }		
    }

    void myGridView_RowDataBound(Object source , GridViewRowEventArgs e)
	{
				//*** Footer ***'
				if (e.Row.RowType == DataControlRowType.Footer) {
						//*** CountryCode ***'
						DropDownList ddlCountryCode = (DropDownList)e.Row.FindControl("ddlAddCountryCode");
						if ((ddlCountryCode != null)) {
							ddlCountryCode.DataSource = (DataTable)DataTableCountryCode();
							ddlCountryCode.DataTextField = "CountryName";
							ddlCountryCode.DataValueField = "CountryCode";
							ddlCountryCode.DataBind();
						}
				}

				//*** Edit ***'

				if (e.Row.RowType == DataControlRowType.DataRow) {
					//*** CustomerID ***'
					TextBox txtCustomerID = (TextBox)e.Row.FindControl("txtEditCustomerID");
					if ((txtCustomerID != null)) {
						txtCustomerID.Text = (string)DataBinder.Eval(e.Row.DataItem, "CustomerID");
					}
					//*** Name ***'
					TextBox txtName = (TextBox)e.Row.FindControl("txtEditName");
					if ((txtName != null)) {
						txtName.Text = (string)DataBinder.Eval(e.Row.DataItem, "Name");
					}
					//*** Email ***'
					TextBox txtEmail = (TextBox)e.Row.FindControl("txtEditEmail");
					if ((txtEmail != null)) {
						txtEmail.Text = (string)DataBinder.Eval(e.Row.DataItem, "Email");
					}
					//*** CountryCode ***'
					DropDownList ddlCountryCode = (DropDownList)e.Row.FindControl("ddlEditCountryCode");
					if ((ddlCountryCode != null)) {
						ddlCountryCode.DataSource = (DataTable)DataTableCountryCode();
						ddlCountryCode.DataTextField = "CountryName";
						ddlCountryCode.DataValueField = "CountryCode";
						ddlCountryCode.DataBind();
						ddlCountryCode.SelectedIndex = ddlCountryCode.Items.IndexOf(ddlCountryCode.Items.FindByValue((string)DataBinder.Eval(e.Row.DataItem, "CountryCode")));
					}
					//*** Budget ***'
					TextBox txtBudget = (TextBox)e.Row.FindControl("txtEditBudget");
					if ((txtBudget != null)) {
						txtBudget.Text = DataBinder.Eval(e.Row.DataItem, "Budget").ToString();
					}
					//*** Used ***'
					TextBox txtUsed = (TextBox)e.Row.FindControl("txtEditUsed");
					if ((txtUsed != null)) {
						txtUsed.Text =DataBinder.Eval(e.Row.DataItem, "Used").ToString();
					}

				}
	}

	void modUpdateCommand(Object sender,GridViewUpdateEventArgs e)
	{
        //*** CustomerID ***//
        TextBox txtCustomerID = (TextBox)myGridView.Rows[e.RowIndex].FindControl("txtEditCustomerID");
        //*** Name ***//
        TextBox txtName = (TextBox)myGridView.Rows[e.RowIndex].FindControl("txtEditName");
        //*** Email ***//
        TextBox txtEmail = (TextBox)myGridView.Rows[e.RowIndex].FindControl("txtEditEmail");
        //*** CountryCode ***//
        DropDownList ddlCountryCode = (DropDownList)myGridView.Rows[e.RowIndex].FindControl("ddlEditCountryCode");
        //*** Budget ***//
        TextBox txtBudget = (TextBox)myGridView.Rows[e.RowIndex].FindControl("txtEditBudget");
        //*** Used ***//
        TextBox txtUsed = (TextBox)myGridView.Rows[e.RowIndex].FindControl("txtEditUsed");

        strSQL = "UPDATE customer SET CustomerID = '" + txtCustomerID.Text + "' " +
            " ,Name = '" + txtName.Text + "' " +
            " ,Email = '" + txtEmail.Text + "' " +
            " ,CountryCode = '" + ddlCountryCode.SelectedItem.Value + "' " +
            " ,Budget = '" + txtBudget.Text + "' " +
            " ,Used = '" + txtUsed.Text + "' " +
            " WHERE CustomerID = '" + myGridView.DataKeys[e.RowIndex].Value + "'";
        objCmd = new OleDbCommand(strSQL, objConn);
        objCmd.ExecuteNonQuery();

        myGridView.EditIndex = -1;
        myGridView.ShowFooter = true;
        BindData();		
	}

</script>
<html>
<head>
    <title>ThaiCreate.Com ASP.NET - GridView</title>
</head>
<body>
<form id="form1" runat="server">
<asp:GridView id="myGridView" runat="server" AutoGenerateColumns="False" 
	ShowFooter="True" 
	DataKeyNames="CustomerID"
	OnRowEditing="modEditCommand"
	OnRowCancelingEdit="modCancelCommand"
	OnRowDeleting="modDeleteCommand"
	OnRowUpdating="modUpdateCommand"
	OnRowCommand="myGridView_RowCommand"
	OnRowDataBound="myGridView_RowDataBound">

	<Columns>

	<asp:TemplateField HeaderText="CustomerID">
		<ItemTemplate>
			<asp:Label id="lblCustomerID" runat="server" Text='<%# DataBinder.Eval(Container, "DataItem.CustomerID") %>'></asp:Label>
		</ItemTemplate>
		<EditItemTemplate>
			<asp:TextBox id="txtEditCustomerID" size="5" runat="server"></asp:TextBox>
		</EditItemTemplate>
		<FooterTemplate>
			<asp:TextBox id="txtAddCustomerID" size="5" runat="server"></asp:TextBox>
		</FooterTemplate>
	</asp:TemplateField>

	<asp:TemplateField HeaderText="Name">
		<ItemTemplate>
			<asp:Label id="lblName" runat="server" Text='<%# DataBinder.Eval(Container, "DataItem.Name") %>'></asp:Label>
		</ItemTemplate>
		<EditItemTemplate>
			<asp:TextBox id="txtEditName" size="10" runat="server"></asp:TextBox>
		</EditItemTemplate>
		<FooterTemplate>
			<asp:TextBox id="txtAddName" size="10" runat="server"></asp:TextBox>
		</FooterTemplate>
	</asp:TemplateField>

	<asp:TemplateField HeaderText="Email">
		<ItemTemplate>
			<asp:Label id="lblEmail" runat="server" Text='<%# DataBinder.Eval(Container, "DataItem.Email") %>'></asp:Label>
		</ItemTemplate>
		<EditItemTemplate>
			<asp:TextBox id="txtEditEmail" size="20" runat="server"></asp:TextBox>
		</EditItemTemplate>
		<FooterTemplate>
			<asp:TextBox id="txtAddEmail" size="20" runat="server"></asp:TextBox>
		</FooterTemplate>
	</asp:TemplateField>

	<asp:TemplateField HeaderText="CountryCode">
		<ItemTemplate>
			<asp:Label id="lblCountryCode" runat="server" Text='<%# DataBinder.Eval(Container, "DataItem.CountryCode") %>'></asp:Label>
		</ItemTemplate>
		<EditItemTemplate>
			<asp:DropDownList id="ddlEditCountryCode" runat="server"></asp:DropDownList>
		</EditItemTemplate>
		<FooterTemplate>
			<asp:DropDownList id="ddlAddCountryCode" runat="server"></asp:DropDownList>
		</FooterTemplate>
	</asp:TemplateField>

	<asp:TemplateField HeaderText="Budget">
		<ItemTemplate>
			<asp:Label id="lblBudget" runat="server" Text='<%# DataBinder.Eval(Container, "DataItem.Budget") %>'></asp:Label>
		</ItemTemplate>
		<EditItemTemplate>
			<asp:TextBox id="txtEditBudget" size="6" runat="server"></asp:TextBox>
		</EditItemTemplate>
		<FooterTemplate>
			<asp:TextBox id="txtAddBudget" size="6" runat="server"></asp:TextBox>
		</FooterTemplate>
	</asp:TemplateField>

	<asp:TemplateField HeaderText="Used">
		<ItemTemplate>
			<asp:Label id="lblUsed" runat="server" Text='<%# DataBinder.Eval(Container, "DataItem.Used") %>'></asp:Label>
		</ItemTemplate>
		<EditItemTemplate>
			<asp:TextBox id="txtEditUsed" size="6" runat="server"></asp:TextBox>
		</EditItemTemplate>
		<FooterTemplate>
			<asp:TextBox id="txtAddUsed" size="6" runat="server"></asp:TextBox>
			<asp:Button id="btnAdd" runat="server" Text="Add" CommandName="Add"></asp:Button>
		</FooterTemplate>
	</asp:TemplateField>

	<asp:CommandField ShowEditButton="True" CancelText="Cancel" DeleteText="Delete" EditText="Edit" UpdateText="Update" HeaderText="Modify"  />
	<asp:CommandField ShowDeleteButton="True" HeaderText="Delete" />
	
	</Columns>
</asp:GridView>
</form>
</body>
</html>