Public Class Form1
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
 
        Me.UsersTableAdapter1.Fill(Me.UserDBDataSet1.Users)
 
    End Sub
 
    Private Sub DataGridView1_CellContentDoubleClick(ByVal sender As Object, _
      ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles _
      DataGridView1.CellContentDoubleClick
        TabControl1.SelectedIndex = 0
        MessageBox.Show("Doppelklick", "Doppelklick", MessageBoxButtons.OK, _
          MessageBoxIcon.Information)
    End Sub
 
End Class