Fill: SelectCommand.Connection property has not been initialized

[santiago8000]

hello,i'm new to vb.net,and i'm trying to do my first program for my training...my program is about the Northwind2 database in sql server,i have a "ShowAll" button,that displays in a form the "Customers" table..i know how to do it using drag and drop datagridview,but i have to write a code by myself to fill it..that's what i wrote and when i push the button i have this error message
"Fill: SelectCommand.Connection property has not been initialized" on this line
"da.Fill(ds, "Customers")"...plz help me quickly,i have to complete the program in 2 days:(...

Private Sub btnShowAll_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnShowAll.Click
//// "this part i wrote it in the class (MainForm) and the form(All) inherits it"
Dim ds As New DataSet
Dim da As New SqlClient.SqlDataAdapter(sql = "SELECT * FROM Customers", con)
Dim sql As String
Dim con As New SqlConnection()//////
All.btnShowAll.Enabled = False
All.Show()
con.Open()
All.DataGridView1.DataSource = ds.DefaultViewManager
sql = "SELECT * FROM Customers"
con.Close()
da.Fill(ds, "Customers")
All.DataGridView1.DataSource = ds.DefaultViewManager
End Sub


thank you:)...