How to Deleting Rows From DataGrid

<!-- The following form displays rows in datagrid along with a checkbox in each row.
Rows can be deleted by turning the checkbox on and then clicking on Delte button --!>


<%@ Page Language="VB" %>
<%@ import Namespace="System.Data,system.Data.SqlClient" %>

<script runat="server">

Dim ConnectionString As String = "uid=sa;database=pubs"

Sub Page_Load(Sender As Object, E As EventArgs)

If Not Page.IsPostBack Then
BindData()
End If

End Sub

Private Sub btnDelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)

Dim i As Integer = 0
Dim cb As CheckBox
Dim dgi As DataGridItem
Dim id As Integer

dim con as new SQlConnection( connectionstring)
con.open()

dim cmd as new SQLCommand("delete from sometable where id = @id",con)
dim p as new SQLParameter("@id",sqldbtype.int)
cmd.parameters.add(p)


For Each dgi In DataGrid1.Items
cb = CType(dgi.findcontrol("chkdelete"), CheckBox)

If cb.Checked Then
id = CType( DataGrid1.DataKeys(i), Integer) ' get primary key
p.value = uid
try
cmd.ExecuteNonQuery()
catch ex as Exception
response.write( ex.message)
end try

End If
i += 1
Next

con.close()

binddata()

End Sub

Sub BindData()

Dim myConnection As New SqlConnection(ConnectionString)
Dim myCommand As New SqlDataAdapter("select * from sometable", myConnection)

Dim ds As New DataSet()
myCommand.Fill(ds)

DataGrid1.DataSource = ds
DataGrid1.DataBind()

End Sub

</script>

<html>
<body>

<form runat="server">
<asp:datagrid id="DataGrid1" runat="server" DataKeyField="id">
<Columns>
<asp:templateColumn>
<headertemplate>Delete</headertemplate>
<itemtemplate>
<asp:checkbox id=chkdelete runat="server"></asp:checkbox>
</itemtemplate>
</asp:templateColumn>
</Columns>
</asp:datagrid>
<p/>
<asp:button id="btndelete" runat="server" text="Delete" onclick="btndelete_click"/>
</form>
</body>
</html>