update a row in datagrid

Replace the statement

        Dim cmd As SqlCommand

with

        Dim cmd As New SqlCommand

You should also add the statement

        cmd.ExecuteNonQuery()

after setting the command properties. This will execute the command against the database. Note that the connection *must* be open before executing the command.

_______________

  Nayer Naguib

i tried the codes.but i didn't get answer.an error occured in  
str1 = CType(e.Item.FindControl("txt"), TextBox).Text
unable to find the textbox.Is there any need to create a textbox in the HTML(code behind)

the code i'm using:

Private Sub datagrid_UpdateCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataGridCommandEventArgs) Handles datagrid.UpdateCommand

        getcon()       'function to get the connection
        Dim str, str1, str2  As String
        Dim txt As New TextBox
        Dim dr As SqlDataReader
        str = datagrid.DataKeys(e.Item.ItemIndex)
        str1 = CType(e.Item.FindControl("txt"), TextBox).Text
        str2 = "update Client set ClientId= " & str1 & " where CurLocation='" & str & "'"
        Dim cmd As New SqlCommand
        cmd.CommandText = str2
        cmd.Connection = con
        dr = cmd.ExecuteReader
        closecon()
        dr.Close()
        datagrid.EditItemIndex = -1
        bindgrid()