The ConnectionString property has not been initialized

Question

for the line:adapter.Fill(datatable)this is for Visual Studio 2013here is the complete code:Public Class ClientsRelation
Private Sub ClientsRelation_Load(sender As Object, e As EventArgs) Handles MyBase.Load
TextBox1.Select()
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
Dim result As DialogResult
result = MessageBox.Show("Sure you Wanna Close ?", "Close?", MessageBoxButtons.YesNo)
If result = System.Windows.Forms.DialogResult.Yes Then
Me.Close()
End If
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim IDNumber As Integer
Dim datatable As New DataTable
If (Me.TextBox1.Text = "") Then
MsgBox("ID Number cannot be in blank", MsgBoxStyle.Critical, "Alert")
Me.TextBox1.Select()
Else
IDNumber = Val(Me.TextBox1.Text)
cmd.CommandType = CommandType.Text
cmd.Connection = con
End If
Using con
Dim adapter As New OleDb.OleDbDataAdapter("Select Clients.IDNumber, Clients.FirstName, Clients.LastName, Clients.Telephone, Clients.Email, Cars.VIN, Cars.ClientIDNumber, Cars.Make, Cars.Model, Cars.Color From Clients Inner Join Cars On Clients.IDNumber = Cars.ClientIDNumber Where IDNumber = " & TextBox1.Text & "", con) adapter.Fill(datatable)
End Using
If datatable.Rows.Count = 0 Then
MsgBox("ID Number Not Found, Please Try Again", MsgBoxStyle.Critical, "Alert")
Else
Me.DataGridView1.DataSource = datatable
End If
End Sub
End Class
how do i fix this error?

Answer 1

Also, you probably don't want to have it in a Using block if it is declared at the module level like that because it will get disposed and then you can't resuse it so it defeats the purpose of putting it in a module (which really isn't necessary
anyway - better to put it in the using statement and end then connection when you are done with it).
Reed Kimble - "When you do things right, people won't be sure you've done anything at all"
this form is part of like 20 other forms. i call the con.open at the start of the first form when it loads and i then i con.close when i exit the program. this way the connection is open the whole time for all the forms.